---
product_id: 463567951
title: "Klein Tools MM420 Auto-Ranging TRMS Digital Multimeter"
brand: "klein tools"
price: "£91.57"
currency: GBP
in_stock: true
reviews_count: 13
category: "Klein Tools"
url: https://www.desertcart.co.uk/products/463567951-klein-tools-mm420-auto-ranging-trms-digital-multimeter
store_origin: GB
region: United Kingdom
---

# 600V AC/DC voltage range 50 MΩ resistance measurement 10A AC/DC current capacity Klein Tools MM420 Auto-Ranging TRMS Digital Multimeter

**Brand:** klein tools
**Price:** £91.57
**Availability:** ✅ In Stock

## Summary

> 🔧 Master your measurements with Klein’s pro-grade precision!

## Quick Answers

- **What is this?** Klein Tools MM420 Auto-Ranging TRMS Digital Multimeter by klein tools
- **How much does it cost?** £91.57 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/463567951-klein-tools-mm420-auto-ranging-trms-digital-multimeter)

## Best For

- klein tools enthusiasts

## Why This Product

- Trusted klein tools brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Built to Last:** Rugged design survives 6.6-foot drops—ready for any job site hustle.
- • **Safety First, Always:** Lead-Alert LEDs ensure correct test lead placement for foolproof safety.
- • **Hands-Free Efficiency:** Kickstand, magnetic hanger & test lead holders keep your workflow seamless.
- • **Precision Meets Power:** Auto-ranging TRMS tech delivers pinpoint accuracy every time.
- • **Work Anywhere, Anytime:** Backlit LCD display guarantees clear readings even in dim environments.

## Overview

The Klein Tools MM420 is a robust, auto-ranging TRMS digital multimeter designed for professionals who demand accuracy and durability. It measures up to 600V AC/DC voltage, 10A AC/DC current, and 50 MΩ resistance, with added functions like temperature, capacitance, frequency, and diode testing. Featuring safety-enhancing lead-alert LEDs, a backlit display for low-light conditions, and a rugged build that withstands 2-meter drops, this tool is engineered for electricians and technicians who need reliable, hands-free operation on any job site.

## Description

Klein Tools MM420 Multimeter is an auto-ranging, true root mean square (TRMS) multimeter that measures AC/DC voltage, AC/DC current, and resistance. It can also measure temperature, capacitance, frequency, duty-cycle, and test diodes and continuity. Klein Tools' Test and Measurement product line was exclusively designed from the ground up by electricians for electricians. Years of field research, combined with extensive input from electricians across America, inspired the development of meters and electrical testers loaded with innovative, time-saving features.

Review: Fantastic Multimeter - I’ve been using the Klein Tools MM420 Digital Multimeter for a bit now, and I’m honestly impressed with how solid and reliable it is. First thing I noticed is the build quality. Like most Klein Tools products, it feels durable and well-made, not like one of those cheap meters that feels like it’ll fall apart if you look at it wrong. The buttons and dial have a good, firm feel, and everything is clearly labeled. The auto-ranging feature is a huge plus. It makes taking measurements quick and simple without having to constantly adjust settings. The readings are fast and consistent, and the True RMS capability gives me confidence that I’m getting accurate results, especially when working with AC circuits. I’ve used it for checking voltage, current, and resistance, and it handles everything without any issues. The display is easy to read, even in less-than-ideal lighting, and the overall layout is intuitive. For the price, this is a great value. It’s reliable, easy to use, and built to last. Whether you’re doing basic troubleshooting or more involved electrical work, this meter gets the job done without any hassle. Definitely one of those tools you buy once and don’t have to think about replacing anytime soon.
Review: Quality that you expect from klein - I have a few different multimeter but this one probably has the most functions on it and is my go to multimeter now. The display is easy to read amd overall easy to use. It lights up where to plug in so there isn't much thinking needed when switching. It's very audible when ohming things and beeps when your forget to turn it off. Great choice for the money

## Features

- VERSATILE FUNCTIONALITY: Measures AC/DC voltage up to 600V, 10A AC/DC current, 50MΩ resistance; additional features include continuity, temperature, capacitance, frequency/duty cycle and diode test
- LEAD-ALERT PROTECTION: LEDs on the meter illuminate to indicate proper test lead placement, enhancing accuracy and safety during measurements
- BACKLIT DISPLAY: LCD shows clear readings in low-light conditions for enhanced visibility
- ACCURATE MEASUREMENTS: Auto-ranging and True Root Mean Squared (TRMS) technology provides precise and accurate measurements
- CONVENIENT FEATURES: Test lead holders on the back of the meter, kickstand and optional magnetic hanger (Cat. Nos. 69445 or 69417) for hands-free operation
- DURABLE CONSTRUCTION: Built to withstand a 6.6-Foot (2 m) drop, ideal for use in basic and controlled electromagnetic environments such as residential, business, HVAC and light-industrial locations
- COMPLETE PACKAGE: Includes test leads with CAT III/CAT IV safety caps, thermocouple, instructions, and 2 x AAA batteries

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0B57PFFYX |
| Best Sellers Rank | #5,713 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #12 in Multi Testers |
| Brand | KLEIN TOOLS |
| Brand Name | KLEIN TOOLS |
| Color | Orange/Black |
| Compatible Devices | Test leads (included with the product) |
| Customer Reviews | 4.7 out of 5 stars 759 Reviews |
| Global Trade Identification Number | 00092644693748 |
| Included Components | Digital Multimeter, Auto-Ranging, 600V |
| Item Dimensions | 9.33 x 5.08 x 3.82 inches |
| Item Highlight | 600V AC/DC Voltage, 10A AC/DC Current, 50 MOhms Resistance |
| Item Type Name | Building Material |
| Item Weight | 14.56 ounces |
| Item dimensions L x W x H | 9.33 x 5.08 x 3.82 inches |
| Manufacturer | Klein Tools |
| Measurement Type | Multimeter |
| Minimum Operating Voltage | 9 volts |
| Model | MM420 |
| Number of Items | 1 |
| Part Number | MM420 |
| Power Source | Battery Powered |
| Specification Met | Cat Iii 600v Safety Rating |
| Style | Auto-Ranging |
| Style Name | Auto-Ranging |
| UPC | 092644693748 |
| Unit Count | 1 Count |
| Upper Temperature Rating | 60 °C |
| Warranty Description | Call vendor for warranty |

## Product Details

- **Brand:** KLEIN TOOLS
- **Color:** Orange/Black
- **Item Weight:** 14.56 ounces
- **Power Source:** Battery Powered
- **Style:** Auto-Ranging

## Images

![Klein Tools MM420 Auto-Ranging TRMS Digital Multimeter - Image 1](https://m.media-amazon.com/images/I/51hgJ2yCwqL.jpg)
![Klein Tools MM420 Auto-Ranging TRMS Digital Multimeter - Image 2](https://m.media-amazon.com/images/I/61qtkmOaOxL.jpg)
![Klein Tools MM420 Auto-Ranging TRMS Digital Multimeter - Image 3](https://m.media-amazon.com/images/I/6180AVes-QL.jpg)
![Klein Tools MM420 Auto-Ranging TRMS Digital Multimeter - Image 4](https://m.media-amazon.com/images/I/51PPCchY4qL.jpg)
![Klein Tools MM420 Auto-Ranging TRMS Digital Multimeter - Image 5](https://m.media-amazon.com/images/I/61KJQVaGbBL.jpg)

## Available Options

This product comes in different **Size** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Fantastic Multimeter
*by Z***H on March 26, 2026*

I’ve been using the Klein Tools MM420 Digital Multimeter for a bit now, and I’m honestly impressed with how solid and reliable it is. First thing I noticed is the build quality. Like most Klein Tools products, it feels durable and well-made, not like one of those cheap meters that feels like it’ll fall apart if you look at it wrong. The buttons and dial have a good, firm feel, and everything is clearly labeled. The auto-ranging feature is a huge plus. It makes taking measurements quick and simple without having to constantly adjust settings. The readings are fast and consistent, and the True RMS capability gives me confidence that I’m getting accurate results, especially when working with AC circuits. I’ve used it for checking voltage, current, and resistance, and it handles everything without any issues. The display is easy to read, even in less-than-ideal lighting, and the overall layout is intuitive. For the price, this is a great value. It’s reliable, easy to use, and built to last. Whether you’re doing basic troubleshooting or more involved electrical work, this meter gets the job done without any hassle. Definitely one of those tools you buy once and don’t have to think about replacing anytime soon.

### ⭐⭐⭐⭐⭐ Quality that you expect from klein
*by J***R on April 7, 2026*

I have a few different multimeter but this one probably has the most functions on it and is my go to multimeter now. The display is easy to read amd overall easy to use. It lights up where to plug in so there isn't much thinking needed when switching. It's very audible when ohming things and beeps when your forget to turn it off. Great choice for the money

### ⭐⭐⭐⭐⭐ Terrific multimeter, with excellent display
*by S***O on October 18, 2024*

A friend gave me his Klein MM 1000. He is an electrician. It was pretty beat up and have been used for many years in a tough environment. I was really impressed with the capabilities of it. However the switch eventually gave up. I wanted to find something similar and was pleased to find the client MM 420. It can "only" deal with up to 600 V circuits, which is not going to be a problem for me. It measures all the important electrical requirements and also includes temperature with an included thermocouple. I bought this one because the display looked really nice, and it is. They changed the LCD color and it really stands out, especially when backlit. Klein multimeter are "bench tested." I put this in quotes because this particular bench test means that they can handle a 3 foot drop off of a bench. I have been happy with every Klein tool I've ever bought. They offer excellent quality at very competitive prices. You can buy very basic all the way up to professional. The fact that my friend, who has been a career electrician, uses Klein multimeter was certainly a plus to me. Very happy with this purchase.

## Frequently Bought Together

- Klein Tools MM420 Digital Multimeter, Auto-Ranging TRMS Multimeter, 600V AC/DC Voltage, 10A AC/DC Current, 50 MOhms Resistance
- WERJIA Hard Carrying Case for Klein Tools MM420/MM325/MM720/MM700/ET600/MM450 Digital Multimeter
- Klein Tools 69417 Rare-Earth Magnetic Hanger, with Strap

---

## 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.co.uk/products/463567951-klein-tools-mm420-auto-ranging-trms-digital-multimeter](https://www.desertcart.co.uk/products/463567951-klein-tools-mm420-auto-ranging-trms-digital-multimeter)

---

*Product available on Desertcart United Kingdom*
*Store origin: GB*
*Last updated: 2026-10-18*