---
product_id: 16621103
title: "5121 FUSE A3T (CLASS T) 400 Amp"
brand: "blue sea systems"
price: "$120.79"
currency: USD
in_stock: true
reviews_count: 13
category: "Blue Sea Systems"
url: https://www.desertcart.us/products/16621103-5121-fuse-a3t-class-t-400-amp
store_origin: US
region: United States of America
---

# 400 Amp high capacity 20,000 Amp interrupt capacity Extremely fast short-circuit response 5121 FUSE A3T (CLASS T) 400 Amp

**Brand:** blue sea systems
**Price:** $120.79
**Availability:** ✅ In Stock

## Summary

> ⚡ Stay powered, stay protected — the fuse pros trust!

## Quick Answers

- **What is this?** 5121 FUSE A3T (CLASS T) 400 Amp by blue sea systems
- **How much does it cost?** $120.79 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/16621103-5121-fuse-a3t-class-t-400-amp)

## 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

- • **Lightning-Fast Safety:** Instant short-circuit response minimizes damage and downtime
- • **Powerhouse Protection:** 400 Amp Class T fuse engineered for heavy-duty DC circuits
- • **Trusted Marine-Grade Quality:** Designed and manufactured by Blue Sea Systems, a leader in electrical safety
- • **Unmatched Interrupt Capacity:** Handles up to 20,000 Amps to safeguard critical systems
- • **Hard-to-Find, Must-Have Spare:** Highly rated and sought-after fuse to keep your system fail-safe

## Overview

The Blue Sea Systems 5121 FUSE A3T (Class T) 400 Amp is a premium, fast-acting fuse designed for high-current DC applications in marine, automotive, and industrial settings. With a 20,000 Amp interrupt capacity and rapid short-circuit response, it ensures maximum protection and reliability. Manufactured in Mexico by Blue Sea Systems, this fuse is a top-rated, essential component for professionals who demand safety and performance.

## Description

GREAT PRODUCT

## Features

- Class T Fuse - 400 Amp
- Extremely Fast Short-Circuit Response
- 20,000 Ampere Interrupt Capacity (Aic)
- Country Of Origin: Mexico

## Technical Specifications

| Specification | Value |
|---------------|-------|
| AC Adapter Current | 400 Amps |
| ASIN | B000MMH1JO |
| Best Sellers Rank | #20,718 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #13 in Cartridge Fuses |
| Brand | Blue Sea Systems |
| Brand Name | Blue Sea Systems |
| Color | Black |
| Current Rating | 400 Amps |
| Customer Reviews | 4.8 out of 5 stars 164 Reviews |
| Global Trade Identification Number | 00632085051211 |
| Included Components | FUSE A3T (CLASS T) 400 AMP |
| Item Dimensions | 2 x 4 x 6 inches |
| Item Type Name | FUSE A3T (CLASS T) 400 AMP |
| Item Weight | 0.1 Pounds |
| Item dimensions L x W x H | 2 x 4 x 6 inches |
| Manufacturer | Blue Sea Systems |
| Material | Plastic |
| Material Type | Plastic |
| Maximum Current | 400 Amps |
| Model | 5121 |
| Mounting Type | Durchsteckmontage |
| Part Number | 5121-BSS |
| Specification Met | Sea |
| UPC | 632085051211 |
| Unit Count | 1.0 Count |
| Voltage | 125 Volts |
| Warranty Description | LIMITED WARRANTY |

## Product Details

- **AC Adapter Current:** 400 Amps
- **Brand:** Blue Sea Systems
- **Item dimensions L x W x H:** 2 x 4 x 6 inches
- **Material:** Plastic
- **Voltage:** 125 Volts

## Images

![5121 FUSE A3T (CLASS T) 400 Amp - Image 1](https://m.media-amazon.com/images/I/71MMZ0hoq1L.jpg)

## Available Options

This product comes in different **Pattern, Style** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Review
*by J***J on May 18, 2025*



### ⭐⭐⭐⭐⭐ Review
*by A***R on October 12, 2024*



### ⭐⭐⭐⭐⭐ Review
*by K***E on January 25, 2026*



---

## 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.us/products/16621103-5121-fuse-a3t-class-t-400-amp](https://www.desertcart.us/products/16621103-5121-fuse-a3t-class-t-400-amp)

---

*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-05-18*