--- product_id: 269370263 title: "Blue Sea Systems MRBF Terminal Fuse Blocks" brand: "blue sea systems" price: "229 zł" currency: PLN in_stock: true reviews_count: 5 category: "Blue Sea Systems" url: https://www.desertcart.pl/products/269370263-blue-sea-systems-mrbf-terminal-fuse-blocks store_origin: PL region: Poland --- # 300A high current rating Stackable M8 stud design Weatherproof for harsh environments Blue Sea Systems MRBF Terminal Fuse Blocks **Brand:** blue sea systems **Price:** 229 zł **Availability:** ✅ In Stock ## Summary > ⚡ Fuse your circuits with confidence — power, protection, and precision in one sleek block! ## Quick Answers - **What is this?** Blue Sea Systems MRBF Terminal Fuse Blocks by blue sea systems - **How much does it cost?** 229 zł with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.pl](https://www.desertcart.pl/products/269370263-blue-sea-systems-mrbf-terminal-fuse-blocks) ## Best For - blue sea systems enthusiasts ## Why This Product - Trusted blue sea systems brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Safety First:** Insulating cap prevents accidental shorts, keeping your system safe and sound - • **Stack & Secure:** Innovative isolated stud design allows neat terminal stacking with standard M8 hardware - • **Space-Smart Design:** Compact footprint fits high-amp fuse protection into tight spaces effortlessly - • **Powerhouse Protection:** Handles up to 300 amps for your critical DC circuits - • **Built for the Elements:** Weatherproof construction ensures reliable performance in open-cockpit boats and tough conditions ## Overview The Blue Sea Systems MRBF Terminal Fuse Block delivers robust 300A current protection with a compact, weatherproof design ideal for marine and harsh environment applications. Featuring a unique isolated M8 stud design for easy terminal stacking and an insulating cap to prevent shorts, it’s engineered for high-performance DC main, inverter, windlass, and bow thruster circuits. ## Description Terminal Fuse BlackNew isolated stud design uses standard 5/16" hardware and permits stacking of terminals Compact, high-amp fuse-Appropriate for DC Main, inverter, windlass, and bow thruster circuit protection Provides high current protection in tight space constraints Weatherproof-suitable for small open-cockpit boats and other harsh environments Insulating cap prevents accidental shorts Use 5/16" or 3/8" ring terminal Review: Neat arrgt. but pricey Review: Blue sea fuse blocks ## Features - New isolated stud design uses standard M8 (5/16") hardware and permits stacking of terminals - Compact, high-amp fuseâAppropriate for DC Main, inverter, windlass, and bow thruster circuit protection - Provides high current protection in tight space constraints - Weatherproofâsuitable for small open-cockpit boats and other harsh environments - Insulating cap prevents accidental shorts ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B0019ZBTV4 | | Best Sellers Rank | #66,519 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #129 in Fuses & Holders | | Brand Name | Blue Sea Systems | | Centerline Length | 2.4 Inches | | Color | Single Fuse | | Colour | Single Fuse | | Connector Type | Screw | | Connector type | Screw | | Country Of Origin | USA | | Current Rating | 300 Amps | | Current rating | 300 Amps | | Customer Reviews | 4.6 out of 5 stars 905 Reviews | | Global Trade Identification Number | 00632085051914 | | Item Dimensions W x H | 6.4W x 5.1H centimeters | | Item Weight | 0.1 Pounds | | Manufacturer | Blue Sea Systems | | Material | Plastic | | Material Type | Plastic | | Model | 5191 | | Mounting Type | Panel Mount | | Mounting type | Panel Mount | | Number Of Contacts | 10 | | Number Of Poles | 1 | | Number of Positions | 1 | | Number of contacts | 10 | | Part Number | 5191 | | Specification Met | Sea | | Temperature Range | -2E+1 Degrees Celsius | | UPC | 632085051914 | | Unit Count | 1 Count | | Upper Temperature Rating | 85 Degrees Celsius | | Voltage | 58 Volts | ## Product Details - **Connector type:** Screw - **Current rating:** 300 Amps - **Material:** Plastic - **Mounting type:** Panel Mount - **Number of contacts:** 10 ## Images ![Blue Sea Systems MRBF Terminal Fuse Blocks - Image 1](https://m.media-amazon.com/images/I/61vPpZ-72JL.jpg) ## Questions & Answers **Q: Does this item come with the fuse terminal included? If so, how do I specify the amperage** A: I just ordered three of these - they each came with a 300A fuse. I was not expecting fuses to be included, so I had ordered them separately. If this is not a shipping/packaging mistake, it would be nice if the seller gave the option to choose a fuse size. While I can use a 300A on one of the terminals, I needed smaller ones for the others. I didn't buy them weeks ago because of the relatively high price of these fuses (typically ~$15 each). They were on sale for $10, so I got them now. **Q: I have a new 100ah 12v lifepo battery. what fuse size do i need to go with this?** A: At solavanbuild, I use 150 amp fuses with 1/0 AWG battery cables in most of my installs. **Q: I'm thinking of running a charge/power wire of the alternator to a trailer battery. Would it be OK to use this off the charge lead on the alternator?** A: I would recommend an automatic Charing Relay ACR. Blue sea makes great ones. I use their Mini-ACR because my boat alternator is less than 65A. Their standard handles up to 300A. Remember regardless, you will need TWO of these fuses, one at each battery. If your alternator puts out 60A then 75A fuses, if it puts out 100A than 130-150A fuses. **Q: Can I use this as a bus bar (without a fuse), just to extend a 5/16 battery terminal. Thank you** A: No you can't.. The stud is insulated from the block.. And don't grind it down. As they are meant for fuses to complete the circuit. Just buy a battery post if you need that... ## Customer Reviews ### ⭐⭐⭐⭐⭐ Neat arrgt. but pricey *by M***T on 9 June 2014* ### ⭐⭐⭐⭐⭐ Blue sea fuse blocks *by T***S on 25 January 2026* ### ⭐⭐⭐⭐⭐ Good battery level protection *by A***R on 30 March 2025* --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.pl/products/269370263-blue-sea-systems-mrbf-terminal-fuse-blocks](https://www.desertcart.pl/products/269370263-blue-sea-systems-mrbf-terminal-fuse-blocks) --- *Product available on Desertcart Poland* *Store origin: PL* *Last updated: 2026-04-25*