--- product_id: 3836489 title: "5191" brand: "blue sea systems" price: "189 zł" currency: PLN in_stock: true reviews_count: 13 category: "Blue Sea Systems" url: https://www.desertcart.pl/products/3836489-5191 store_origin: PL region: Poland --- # 300A max current Weatherproof marine-grade 5/16" terminal stud 5191 **Brand:** blue sea systems **Price:** 189 zł **Availability:** ✅ In Stock ## Summary > ⚡ Elevate your power game with marine-grade fuse protection! ## Quick Answers - **What is this?** 5191 by blue sea systems - **How much does it cost?** 189 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/3836489-5191) ## 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 - • **Safe & Secure:** Insulating cap prevents accidental shorts, ensuring peace of mind - • **Ignition Ready:** Ignition protected when paired with MRBF fuses for reliable starts - • **Powerhouse Protection:** Handles up to 300 amps for your high-demand circuits - • **Built for the Elements:** Weatherproof design perfect for harsh marine and open-cockpit environments - • **Plug & Play Simplicity:** Universal fit with clear amperage labeling for effortless installation ## Overview The Blue Sea Systems 5191 Fuse Block Terminal is a compact, weatherproof DC fuse block designed for 30–300A MRBF fuses. It offers robust overcurrent protection for boat and vehicle electrical systems, featuring corrosion-resistant materials, a 5/16" terminal stud, and an insulating cap to prevent shorts. Ideal for high-capacity battery banks and accessory loads, it supports easy installation and ignition protection when used with MRBF fuses. ## Description Fuse Block, Battery Post Mount, 1 stud, MFG# 5191, Accepts MRBF fuses from 30-300 Amp. Mounts on 3/8" (MN10) Battery Post, single 5/16" stud for wire connections. Fuse not included. Review: Quality product - Quality product. Works as intended. Review: Solid build, good quality - Solid build, good quality. Made by EATON Austria. ## Features - Voltage Max Operating: 58V DC, Amps Max Operating: 300A per block, Terminal Fuses Avail.: 30A-300A, Terminal Stud Size: 5/16"-18 (8mm), Mounting Hole Size: 10 (5mm)3/8" - Compact, high-amp fuse—appropriate for DC Main, inverter, windlass, and bow thruster circuit protection - Weatherproof – suitable for small open-cockpit boats and other harsh environments - Insulating cap prevents accidental shorts - Ignition protected when used with MRBF fuses - Fuses sold separately - Fit type: Universal Fit ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B0019ZBTV4 | | Best Sellers Rank | #10,253 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #2 in Fuse Blocks (Tools & Home Improvement) | | Brand Name | Blue Sea Systems | | Color | Single Fuse | | Connector Type | Screw | | Current Rating | 300 Amps | | Customer Reviews | 4.6 out of 5 stars 951 Reviews | | Gauge | 1.0 | | Global Trade Identification Number | 00632085051914 | | Included Components | Blue Sea Systems 5191-BSS MRBF Terminal Fuse Block - 30A-300A | | Item Dimensions W x H | 2.5"W x 2"H | | Item Pitch | 8 Millimeters | | Item Type Name | Blue Sea Systems 5191-BSS MRBF Terminal Fuse Block - 30A-300A | | Item Weight | 0.1 Pounds | | Manufacturer | Blue Sea Systems | | Material Type | Plastic | | Model | 5191 | | Mounting Type | hole mount | | Number Of Contacts | 10 | | Number Of Poles | 1 | | Number of Positions | 1 | | Part Number | 5191-BSS | | Pitch | 8 Millimeters | | Specification Met | Sea | | UPC | 632085051914 | | Unit Count | 1.0 Count | | Voltage | 58 Volts | ## Product Details - **Brand:** Blue Sea Systems - **Color:** Single Fuse - **Connector Type:** Screw - **Current Rating:** 300 Amps - **Gauge:** 1.0 - **Material:** Plastic - **Mounting Type:** hole mount - **Number Of Contacts:** 1 - **Number Of Poles:** 1 - **Voltage:** 58 Volts ## Images ![5191 - Image 1](https://m.media-amazon.com/images/I/61vPpZ-72JL.jpg) ![5191 - Image 2](https://m.media-amazon.com/images/I/41wSzfaD3cL.jpg) ## Available Options This product comes in different **Color, Style** options. ## 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 ### ⭐⭐⭐⭐⭐ Quality product *by I***E on April 11, 2026* Quality product. Works as intended. ### ⭐⭐⭐⭐⭐ Solid build, good quality *by I***V on April 23, 2026* Solid build, good quality. Made by EATON Austria. ### ⭐⭐⭐⭐⭐ Expanding Lynx Distributor Capacity with a Key Addition *by V***S on October 20, 2023* The Blue Sea Systems 5191 Fuse Block Terminal has been nothing short of a revelation for my power management setup. I invested in this brilliant solution to seamlessly integrate my Dometic RTX2000 air conditioner into my Lynx distributor by Victron. The challenge with the Lynx distributor was its limited available slots, necessitating the addition of another Lynx—an expensive and space-consuming proposition. The Blue Sea Systems fuse block terminal provided an elegant and straightforward solution. By attaching it to the end of the Lynx and securely fastening it with a simple bolt-down mechanism, I was able to connect the air conditioner to the Victron system. This small yet critical addition allowed me to not only connect the air conditioner but also monitor its current, draw, and amperage. In the past, the air conditioner was directly linked to the battery, leaving me guessing about its power consumption, which was far from ideal. It's essential to note that when installing the Blue Sea Systems 5191 Fuse Block Terminal, make sure you don't over-tighten the fasteners. Refer to the manufacturer's torque specifications to ensure a secure yet safe installation. In a nutshell, the Blue Sea Systems 5191 Fuse Block Terminal is a must-have addition for anyone aiming to optimize their power management system. It's a versatile, user-friendly solution that resolves common power distribution challenges. I wholeheartedly recommend this product to fellow enthusiasts who wish to take the guesswork out of power monitoring and improve energy efficiency. It's a true game-changer, delivering on its promises and ensuring a more streamlined and efficient power setup, with a vital caution for installation. --- ## 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/3836489-5191](https://www.desertcart.pl/products/3836489-5191) --- *Product available on Desertcart Poland* *Store origin: PL* *Last updated: 2026-05-25*