SKU: 76529175663

MAXX CNC Aluminum Hopup Chamber M4P - PRO (for Polar Star)

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Description

MAXX CNC Aluminum Hopup Chamber M4P - PRO (for Polar Star)Product Description CNC Aluminum Hopup Chamber M4P Pro (with BB Latching System) unit is precisely machined to perform accurately and consistently with HPA PolarStar Engines on standard M4 M16 platform. The Hopup Chamber M4P unit is built with an aluminum Rotary Dial Knob for fine hopup adjustments, the precision Hopup Lever and 4mm Bucking Nubs (6mm Bucking Nubs are optional) to perform best with R Hop and Standard Hop to keep the BB shooting

Product Description

 

CNC Aluminum Hopup Chamber M4P Pro (with BB Latching System) unit is precisely machined to perform accurately and consistently with HPA PolarStar Engines on standard M4/M16 platform.
The Hopup Chamber M4P unit is built with an aluminum Rotary Dial Knob for fine hopup adjustments, the precision Hopup Lever and 4mm Bucking Nubs (6mm Bucking Nubs are optional) to perform best with R-Hop and Standard-Hop to keep the BB shooting accurately and consistently on every single shot.
The Hopup Chamber M4P unit is designed to accept the HPA PolarStar Engine M4 nozzle length, and fully compatible with most aftermarket soft and hard rubber buckings without losing FPS or dropping BB during use.
The Hopup Chamber M4P unit is wisely equipped with an interchangeable Inlet Adaptor OD11mm to ensure the hopup unit is inserted exactly in the center of the 11mm inner bore HPA Engine nozzle outlet without wobbling. (Inlet Adaptor OD11.5mm and OD12mm are optional)
Also mounted the removable CNC Brass Side Wings to slide smoothly into the outer barrel slots, and included an advanced CNC Delrin Locking C-Clip to hold the inner barrel tight in place without wobbling and twisting.
More than that, the Hopup Chamber M4P Pro unit is specially designed with a new BB Latching System to prevent BB dropping after removing the magazine. The Latching Arm can also be manually pressed to release the remaining BB from inside the hopup chamber.

***The Dual UV LED Tracer Module is an add-on option to glow BB in the dark. Operating Voltage from 7VDC - 15VDC (2-4 cells LiPo, 6-13 cells NiCad). (Sold separately)
***Test results: FPS might be increased from 10FPS to 30FPS over the stock setup. Please check your FPS!

 

  Includes
1 x CNC Aluminum Hopup Chamber M4P Pro (with BB Latching System) unit
2 x CNC Acrylic Side Cover
2 x CNC Brass 2.5mm Side Wing
1 x CNC Steel Pivot Pin
1 x CNC Aluminum Hopup Lever
1 x CNC Aluminum Soft Round Nub
1 x CNC Aluminum Soft Flat Nub (4mm)
1 x CNC Aluminum Hard Concave Nub (4mm)
3 x Steel Nub Spring
1 x CNC Steel Spring Guide
1 x Steel Upper Compression Spring
1 x Steel Center Compression Spring
1 x CNC Delrin Locking C-Clip
1 x CNC Brass Barrel Spacer
1 x Brass Barrel Spacer Holder Oring
1 x CNC Aluminum Rotary Dial Knob
1 x CNC Aluminum Inlet Adaptor (OD11mm)

 

  Specification
Overall Length: 51.15mm
Overall Height: 37.75mm
Inlet Adaptor Outer Diameter (to fit into HPA Nozzle Outlet): 11mm
Hub Outer Diameter (to fit into Outer Barrel): 12mm
Hub Inner Diameter (to fit Nozzle): 8mm
Feeder Outer Diameter (to fit magazine): 8.85mm
Feeder Length (to fit magazine): 6mm
Material: Aluminum 6061

 

  Features
Machined from a solid aircraft aluminum block with tight tolerances to achieve the most accuracy, consistency, and durability
Performed accurately and consistently with HPA PolarStar Engines on standard M4/M16 platform
Precision Rotary Dial Knob for fine hopup adjustments
Re-engineered the precision Hopup Lever and 4mm Bucking Nubs (6mm Bucking Nubs are optional) to perform best with R-Hop and Standard-Hop to keep the BB shooting accurately and consistently on every single shot
Removable Steel Pivot Pin for ease of setup and maintenance
Accepted the HPA PolarStar Engine M4 nozzle length
Fully compatible with most aftermarket soft and hard rubber buckings without losing FPS or dropping BB during use
Wisely equipped with an interchangeable Inlet Adaptor OD11mm to ensure the hopup unit is inserted exactly in the center of the 11mm inner bore HPA Engine nozzle outlet without wobbling. (Inlet Adaptor OD11.5mm and OD12mm are sold separately)
Mounted the removable CNC Brass Side Wings to slide smoothly into the outer barrel slots
Included an advanced CNC Delrin Locking C-Clip to hold the inner barrel tight in place without wobbling and twisting
Equipped with 2 compression springs on top and center to ensure the hopup unit is seated straight and air tight during use
Specially designed with a new BB Latching System to prevent BB dropping after removing the magazine
The Latching Arm can also be manually pressed to release the remaining BB from inside the hopup chamber
Compatible with any 11mm inner bore HPA Engine nozzle outlets
The Dual UV LED Tracer Module to glow BB in the dark ready!

 

  Weight
N/A grams

 

  Usage
Compatible with most HPA PolarStar Engines on standard M4/M16 platform

 

  Requires
Wearing eye protection is recommended
Use proper tools for disassembly and reassembly the gear box with great care due to spring tension
Bearing lubricant oil/grease is recommended for smooth operation

 

  Instruction
Instruction Manuals are included

 

PolarStar Airsoft is a division of PolarStar Engineering & Machine (PSE&M).
Shipping Notes
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  • Except Preorder products are shipped in 48 hours.
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Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
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SKU: 76529175663

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4.5 ★★★★★
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BlackHeartNY
Draper, US
★★★★★ 5
It’s a God Send
I had a rash all around my lips and my lips got extremely dried out and started to peel. I used Avene Cicalfate Restorative Lip Cream and it really soothed my lips with the moisture they needed, and you don’t need to use a lot of this product. I plan on buying this again. Just wish the tube was bigger! I use other Avene products and I’m extremely happy with them.
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Reviewed in the United States on April 6, 2026
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Audra K
Whiting, US
★★★★★ 5
Holy Grail Moisturizer for Rosacea
Style: Restorative Protective Cream-3.3 Fl Oz
In seeing so many negative reviews I felt compelled to weigh in as this is my favorite moisturizer. I have very dry, menopausal skin. Additionally, I have rosacea which seems to have been a nice gift from said menopause (you can only laugh, right?). It's very common for those of us in our 50's to have a compromised skin barrier and when an issue like rosacea is present, even more so. Because of all this my skin is very intolerant to most moisturizers and nearly all actives (over the last few years I've had to discontinue my retinols and chemical exfoliators). While ingredients like ALA's, petrolatum, mineral oil, parafin/bees wax, and lanolin are well tolerated and known to be quite soothing, they don't hydrate very well as they are more occlusive than moisturizing. Enter this product. Magically, it does both! It's marketed as a protective cream, which again implies occlusive, but it penetrates like no other. Gone is the tight, dry feeling that persisted even when I had a heavy layer of product on my skin (my previous moisturizer was Eucerin Original Healing Cream -- which still has its uses -- because it was the only thing I could put on my skin outside of squalane oil during a flare). Now, no topical can cure rosacea. However, the right product can calm the skin, repair the damaged lipid barrier, and improve its appearance. This moisturizer does just that and it's become my holy grail. Since starting this I've also added in the Cicalfate Serum which has only aided in repairing my skin. Another Avene product that works great for me is the XeraCalm Balm which helps with itching. I use all three of these daily and they've really helped fix the secondary issues that come with rosacea. As for the complaints about it being greasy or too heavy. I can see this not working for people with normal or oily skin (or perhaps only in moderation). But my skin loves the heavier weight and because one of the ways I soothe a flare is to keep a tiny mister bottle on hand and repeatedly spray my face so I have to guard against the drying effects of evaporation. These products are so lipid heavy that I can wet my face all day long without worrying about that, though I do reapply throughout the day. As for the watery consistency issue, I haven't had that problem but it does caution on the packaging not to expose the product to temperatures below 41 degrees F (5 C). I suspect that if it gets too cold either because of the weather or because of whatever warehouse it sat in during transit it will separate. Maybe open the package and before squeezing some out look to see if it has split and then shake it up/message the tube. So, if you have skin like mine don't hesitate to try this product. I'm leaving this absurdly long review for my struggling brothers and sisters out there with rosacea in hopes that it provides some relief! Happy moisturizing, internet strangers. ;)
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Reviewed in the United States on July 18, 2025
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Tobyizme
Charlottesville, US
★★★★★ 4
Possible solution to seperation
Style: Restorative Protective Cream-1.3 Fl Oz
I love this product so much, but, like everyone else the water HEAVILY separated. A lot of water just shot out immediately and as i've used the cream it has felt more and more thick bc of that, shaking the tube or not. POSSIBLE SOLUTION: I actually think the company could salvage this problem by upgrading packaging to a Cosmetic JAR and then customers could take a toothpick and stir if separation has occurred by the time of purchase. I hope to try this with my next tube, just toothpaste squeezed everything out into a nice cosmetic jar and stir the water back into the product. This is such a simple solution that could really solve the product waste. This refreshes my skin, doesn't break me out, and is lovely. I break out so easily, and being middle aged my skin really requires a dense help with moisture. <3
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Reviewed in the United States on April 22, 2026
T
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Tara Tadema
Alexandria, US
★★★★★ 5
Ordered in spring/summer and it arrived separated too BUT...
Style: Restorative Protective Cream-1.3 Fl Oz
Ok, So I heard great things about this cream and decided to order. I ordered on May 28th and I live on the Gulf Coast of Texas and it is in the low 90s right now. I was worried mine would arrived separated like many others claimed to have gotten theirs, and sadly it did. Warm weather or not, blue water shot out of the tube the minute I squeezed it. Luckily, I read Mia P's review and submerged my tube in warm water (hot water actually straight out of my instant hot water faucet). I left it for about 5 minutes then shook it vigoroously. It seemed to help but was still a bit wonky so I repeated the process again and success! My tube is totally fine now and comes out in a thick, rich, emollient cream as it is supposed to. I will update my review after I use it more but so far I love the way it feels on the skin. It is very thick but spreads nicely and completely absorbs into the skin and leaves no greasy residue which is a big deal because I have oily skin. I purchased this to help with my Retin A uglies (I actually am using Musely with .05% tretinoin) and am hoping it helps with the redness and peeling I am having. I will update my review once I've used it for a while but wanted to post this review as I saw so many people complaining about the separating and just thought I'd mention that you can fix this issue if you have it (and there is a good likely hood that you will). Update: I've been using this for a week now and I am absolutely in love with this cream! It is the most hydrating and healing cream I've ever used. Usually, thicker face creams like this would cause issues for me with acne or clogged pores as I do have oily skin that can break out if I use products with occlusive ingredients, but this one does not. In fact, my skin has never looked better! This is a must-have if you are using Retin-A/Tretinoin and going through the red/peely phase with your skin. The separation that occurred when I first received it has not been a problem and the cream is staying thick and free from any strange liquidy issues after I put it in hot water as mentioned in the first part of my review.
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Reviewed in the United States on May 28, 2023
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Verified Purchase
hellsbellstrudy
Los Angeles, US
★★★★★ 5
Saved My Skin and Healed My Eczema
Style: Restorative Protective Cream-1.3 Fl Oz, Style: Restorative Protective Cream-1.3 Fl Oz
I was having the worst skin winter of my life. I am hypersensitive and my skin started rejecting an expensive line I had used for many years (EL). My skin wasn’t healing even just using AQ balm on it and occasionally steroids when it was extra bad, and the pronounced eczema on my eyelids and neck for months was making me miserable and gross looking. I started researching brands I hadn’t tried for super sensitive skin and saw recommendations for Avene. We were leaving on a vacation and I was desperate to feel better so I ordered this and the matching serum. I started with only this cream and overnight I saw my skin start to heal. Within a few days it was like the last few months never happened. I carefully added the serum and had no issues. I used only these two products for the month I was gone and had glowing skin the whole time. This is thicker than a normal lotion since it is made to protect your skin but if you let it warm up a few seconds it smoothes easily. This will definitely remain a staple in my skin arsenal and I can’t thank you enough for making an actually gentle but effective product! This picture is two weeks after starting the product, smooth skin and confident to take selfies!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 3, 2026

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