SKU: 19559351091

Blue Sea 300A Red Mini m-Series On/Off Battery Switch w/ Lockable Key

Sale price$51.54 Regular price$57.27
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Ships within 48 hours · Estimated delivery Aug 23 - Aug 28

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Description

Blue Sea 300A Red Mini m-Series On/Off Battery Switch w/ Lockable KeySecure High Current Switching for Marine and Vehicle Systems The Blue Sea m Series Battery Switch sets the standard for compact, high performance power isolation. Designed for marine, caravan, and RV applications, this switch manages a single battery bank, allowing users to safely disconnect power during maintenance or storage. With a continuous rating of 300 Amps, it is perfectly sized for outboards, small petrol engines, and diesel engines,

Secure High-Current Switching for Marine and Vehicle Systems

The Blue Sea m-Series Battery Switch sets the standard for compact, high-performance power isolation. Designed for marine, caravan, and RV applications, this switch manages a single battery bank, allowing users to safely disconnect power during maintenance or storage. With a continuous rating of 300 Amps, it is perfectly sized for outboards, small petrol engines, and diesel engines, providing robust power handling without the bulk of industrial-grade switches.

Integrating a battery switch is essential for preserving battery life. By turning the switch to the 'Off' position, you eliminate parasitic loads that slowly drain batteries over time. This ensures that when you return to your boat or vehicle, your power system is ready to go. Its compact form factor allows for installation in tight spaces where traditional heavy-duty switches cannot fit.

Lockable Security for Safety and Theft Prevention

A standout feature of this specific model is the lockable key mechanism. Unlike standard rotary switches, this unit includes a removable key that secures the switch in the 'Off' position. This functionality provides two critical benefits: enhanced security and maintenance safety.

For vessel or vehicle owners, the key acts as a theft deterrent, preventing unauthorised use of the engine or electrical system. For technicians and DIY enthusiasts, it serves as a safety lockout, ensuring the circuit cannot be accidentally energised while working on the electrical system. This reduces the risk of short circuits and electrical shock during repairs.

Engineered for Harsh Environments

Reliability in marine environments requires superior materials. The m-Series uses tin-plated copper studs to offer maximum conductivity while resisting corrosion caused by salt mist and humidity. The studs feature a one-piece design, which is a significant improvement over standard two-piece bolts. This design ensures the stud never loosens from the switch body over time, maintaining a solid electrical connection and reducing the risk of overheating—a common point of failure in generic switches.

The unit is housed in a reinforced casing with an isolating cover that protects the rear contacts from accidental shorting. Breakout tabs on the cover allow for wire access in any direction, simplifying the wiring process in complex setups.

Versatile Connection Options

The switch is designed to accommodate modern heavy-duty cabling. The 3/8" (Approx. M10) stud terminals are robust enough to accept heavy-duty lugs, ensuring secure, low-resistance connections. With a stud length of 7/8" (22 mm), the terminals can accept multiple cable lugs, allowing for easy integration of additional loads or charging sources directly at the switch.

  • 300 Amps continuous rating handles substantial 12V, 24V, and 48V loads comfortably.
  • Lockable key design prevents accidental activation and enhances security.
  • Tin-plated copper studs ensure maximum corrosion resistance and electrical flow.
  • One-piece terminal studs prevent loosening, reducing fire risks and connection failures.
  • Flexible mounting with breakout tabs supports various cable entry angles.
  • Ignition protected marking makes it safe for installation aboard petrol-powered boats.

Improve System Safety Today

Upgrade your battery management system with the Blue Sea m-Series Lockable Switch. Whether you need to secure a vehicle against theft or ensure safe isolation for maintenance, this switch delivers professional-grade performance in a compact package.

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
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]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 19559351091

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capkafamily
Belleville, US
★★★★★ 2
Crop- short hem
Color: Brown, Size: Large
Great fit but CROP! Doesnt look like photos at all. Fits beautifully everywhere but hem stops at top of my pants. I am 5'7"
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Reviewed in the United States on December 25, 2025
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Melody L. Collamer
Massapequa, US
★★★★★ 3
Good quality. But dont down size
Color: Brown, Size: Small
Cute but too small on me. I ordered a Small by mistake from
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Reviewed in the United States on November 3, 2025
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Stephanie B.
Dallas, US
★★★★★ 5
Cute sweater but runs short
Color: Brown, Size: Large
This is a soft sweater with cute slight ballon sleeve. The color is a true brown stripe. The downside is that the length is a bit short, hitting about 2-3 inches below the belt. I’m self conscious about my belly so I like longer sweater. The Henley style is a nice departure from the typical crew or Vneck.
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Reviewed in the United States on November 15, 2025
T
Verified Purchase
They are OK for the price half of them were missing the slits for the pens, compact and nice colors though.
Boise, US
★★★★★ 5
Elevated Casual
Color: Navy, Size: Large
Looks very J.Crew without the price. The stitching feels higher quality, the knitted fabric does feel slightly cheap but that would be expected. Simple way to elevate an outfit. True to size, but have not washed yet.
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Reviewed in the United States on February 17, 2026
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TripletMama Heather
San Leandro, US
★★★★★ 5
Perfect for casual wear and dressy style
Color: Dark Green, Size: Small
This sweater is soooo soft and the color is so rich. The fit of it is perfect, not too tight and not too baggy, just right and I used the size guide to pick my size. Just for reference, I am 5'3" and 130lbs, 38C bust. It's well made and washes great. I chose to hang dry mine as I typically don't put any of my sweaters in the dryer to dry, just to fluff them. I have this one in two colors, the green and the tan/beige and I would say they are both a true representative of the color shown.
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Reviewed in the United States on November 15, 2025

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