Orders over £85 qualify for FREE SHIPPING! For UK Mainland - For general queries please call 0121 236 5012
The Fusebox F3021MZ (Replaces Fusebox F2020MX) is a 21-way RCBO consumer unit equipped with a 100A main switch and a Type 2 Surge Protection Device (SPD). Designed to guard against transient over-voltages and lightning strikes, it features Fusebox’s advanced SPD1MT2 device, which connects directly to the busbar—eliminating the need for a miniature circuit breaker and enhancing both safety and ease of installation.
Designed for Streamlined Installation
Like with the rest of the Fusebox line, the Fusebox F3021MZ is installer-friendly with a variety of 20–40mm knockouts for flexible cabling options.
Built to Last
Fully compliant with BS EN 61439-3 standard, rated IP2XC for electrical safety and constructed from rust-resistant galvanised steel, this unit combines durability with trusted performance.
Popular products from our range.
WHY CHOOSE SND ELECTRICAL
See what sets us apart from other electrical retailers.
We've spent decades building a reputation for quality stock, fair prices, and exceptional service.
Call us Monday to Saturday for anything you need.
We stock over 30,000 items from trusted manufacturers.
Most orders dispatched within 1-3 working days.
70+ years of experience supplying electrical products
If you need more information, you can find it right here.
Standard delivery takes 3-7 working days, or you can choose speedy delivery (£8.95) for 1-3 working days. Orders over £85 qualify for free standard shipping to UK mainland addresses. We'll email you when your order is dispatched with tracking details.