---
product_id: 3671934
title: "Master Lock Red Electrical Box Circuit Breaker Lockout, Tagout Breaker Box Lock for Standard Single and Double Toggles, 493B, 24 Amps"
brand: "master lock"
price: "HK$130"
currency: HKD
in_stock: true
reviews_count: 8
category: "Master Lock"
url: https://www.desertcart.hk/products/3671934-master-lock-red-electrical-box-circuit-breaker-lockout-tagout-breaker
store_origin: HK
region: Hong Kong
---

# Fits 120V & 240V breakers Patented Grip Tight™ lock Durable powder-coated steel Master Lock Red Electrical Box Circuit Breaker Lockout, Tagout Breaker Box Lock for Standard Single and Double Toggles, 493B, 24 Amps

**Brand:** master lock
**Price:** HK$130
**Availability:** ✅ In Stock

## Summary

> 🔐 Lock it tight, work with confidence — safety that means business.

## Quick Answers

- **What is this?** Master Lock Red Electrical Box Circuit Breaker Lockout, Tagout Breaker Box Lock for Standard Single and Double Toggles, 493B, 24 Amps by master lock
- **How much does it cost?** HK$130 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.hk](https://www.desertcart.hk/products/3671934-master-lock-red-electrical-box-circuit-breaker-lockout-tagout-breaker)

## Best For

- master lock enthusiasts

## Why This Product

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

## Key Features

- • **Built to Endure:** Powder-coated steel and reinforced polymer withstand harsh industrial environments.
- • **OSHA-Ready Safety:** Integrates seamlessly into comprehensive lockout/tagout safety programs for compliance.
- • **Compact & Portable:** Slim 5-inch design fits easily in toolkits for on-the-go professional use.
- • **Effortless Lockdown:** Patented Grip Tight™ design secures breakers with a simple thumb turn and clamp.
- • **Universal Compatibility:** Fits standard single and double toggle breakers on 120V and 240V circuits.

## Overview

The Master Lock 493B Circuit Breaker Lockout is a compact, durable lockout/tagout device designed for standard single and double toggle breakers on 120V and 240V circuits. Featuring a patented Grip Tight™ mechanism, it ensures secure, easy locking with a thumb turn and clamp. Constructed from powder-coated steel and reinforced polymer, it withstands tough environments and accepts all Master Lock and American Lock safety padlocks, making it an essential OSHA-compliant safety tool for professionals.

## Description

Master Lock 493B Lockout Tagout Circuit Breaker Lockout, Standard Single and Double Toggles fits standard height and tie-bar toggles typically found on 120 and 240 volt breakers. The innovative patented Grip Tight™ design effectively locks out circuit breakers with a simple thumb turn and then close clamping handle for a tight grip on the toggle. Device accepts all American Lock® and Master Lock® safety padlocks and most lockout hasps for full lockout. Durable construction and red color with powder coated steel and reinforced polymer stands up in harsh environments. Compact circuit breaker lockout design is easy to carry and store.

Review: So Simple And Effective - I bought this breaker lock-out as a reminder to not turn this breaker on, unless you really need it. I use this on the 240V, 50 AMP, Electric Vehicle / Recreational Vehicle outlet that I installed under our breaker panel. Most of the time, this should be turned OFF, but on rare occassion it needs to be turned on. This Lock-out makes it really easy to remember to keep it turned Off when not needed and prevents people from turning it on by accident. The quality of construction is excellent and although I didn't need to use the fitment accessories that came with it, I appreciate that they were included. Nothing is as frustrating as not being able to finish a project beause of a fitment issue. Master Lock had this in mind and they have you covered. Great little product. I would definately buy it again.
Review: Great Product - I'm an electrician, I use these whenever I work on a job. It keeps someone from flipping on the breaker while I'm working on the circuit. They work perfectly.

## Features

- Lockout tagout circuit breaker lockout is best used on standard height and tie-bar toggles typically found on 120 and 240 volt breakers; Best used as part of a comprehensive OSHA compliant lockout tagout safety program
- Innovative patented Grip Tight design effectively locks out circuit breakers with a simple thumb turn and then close clamping handle for a tight grip on the toggle
- Durable construction with powder coated steel and reinforced polymer for operation in harsh environments
- 5-1/8 in. (13 cm) long circuit breaker lockout with 1-3/16 in. (3 cm) height and 2-3/4 in. (7 cm) depth
- Includes one lockout tagout circuit breaker lockout; Accepts all Master Lock and American Lock safety padlock shackles and lockout hasps (padlocks and hasps sold separately)

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B004J173I8 |
| Best Sellers Rank | #4,941 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #2 in Lockout & Tagout Devices |
| Brand | Master Lock |
| Brand Name | Master Lock |
| Circuit Breaker Type | Standard |
| Current Rating | 24 Amps |
| Customer Reviews | 4.6 out of 5 stars 1,633 Reviews |
| Global Trade Identification Number | 00071649229725 |
| Included Components | Unit^Instruction Guide |
| Item Dimensions D x W x H | 5"D x 3"W x 1"H |
| Item Type Name | Lockout Tagout Device Circuit Breaker Lockout |
| Item Weight | 0.05 Kilograms |
| Manufacturer | Master Lock |
| Model | 493 |
| Mounting Type | Tie-bar |
| Number Of Poles | 1 |
| Number of Poles | 1 |
| Product Dimensions | 5"D x 3"W x 1"H |
| UPC | 071649229725 |
| Unit Count | 1.0 Count |
| Voltage | 240 Volts |

## Product Details

- **Brand:** Master Lock
- **Circuit Breaker Type:** Standard
- **Current Rating:** 24 Amps
- **Mounting Type:** Tie-bar
- **Product Dimensions:** 5"D x 3"W x 1"H

## Images

![Master Lock Red Electrical Box Circuit Breaker Lockout, Tagout Breaker Box Lock for Standard Single and Double Toggles, 493B, 24 Amps - Image 1](https://m.media-amazon.com/images/I/41KEk6QWrzL.jpg)

## Available Options

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

## Questions & Answers

**Q: Will these fit double pole breakers or just single pole?**
A: It would fit over one side of most 2-pole breakers, which would, in effect,  lock out the breaker.  This does not fit some larger 277V breakers.

**Q: Can this be knocked off with a hammer or pried off with a screwdriver?  I need it to be secure!**
A: All  the person you’re trying to prevent from using the electrical needs to do is remove the entire circuit breaker that has the lock on it  and replace it with another breaker to continue to use electricity. Not even locking the wall panel will help, the cover is held on with 4 screws

Your only opinion you have left is to place a metal cap over the breaker switch and connect the metal cap to the 220 feed leading into the panel

**Q: how wide does the jaws open?**
A: It's ment for a breaker. It will fit any breaker from the main power to the 15 and 20 amp ones

**Q: i need a device to lock breaker in on position to insure our church organ is not turned off accidently can i reverce this device to use it that way???**
A: This device is probably not what you want---it is intended to lock a circuit breaker in the "OFF" position for safe-maintenance situations...they make a breaker lock intended for locking a breaker in the "ON" position...it is intended for applications such as you describe---an alarm system, eg.,...the breaker will still trip if overloaded, but cannot be turned off by accident or un-authorized personnel.

## Customer Reviews

### ⭐⭐⭐⭐⭐ So Simple And Effective
*by A***Z on October 6, 2023*

I bought this breaker lock-out as a reminder to not turn this breaker on, unless you really need it. I use this on the 240V, 50 AMP, Electric Vehicle / Recreational Vehicle outlet that I installed under our breaker panel. Most of the time, this should be turned OFF, but on rare occassion it needs to be turned on. This Lock-out makes it really easy to remember to keep it turned Off when not needed and prevents people from turning it on by accident. The quality of construction is excellent and although I didn't need to use the fitment accessories that came with it, I appreciate that they were included. Nothing is as frustrating as not being able to finish a project beause of a fitment issue. Master Lock had this in mind and they have you covered. Great little product. I would definately buy it again.

### ⭐⭐⭐⭐⭐ Great Product
*by N***J on July 27, 2025*

I'm an electrician, I use these whenever I work on a job. It keeps someone from flipping on the breaker while I'm working on the circuit. They work perfectly.

### ⭐⭐⭐⭐⭐ Simple Solution
*by J***3 on January 18, 2026*

Simple circuit lock. Easy to use. It does inhibit me from closing box cover due to height when it's attached to breaker but that is no fault of the product. Very happy with purchase.

## Frequently Bought Together

- Master Lock Red Electrical Box Circuit Breaker Lockout, Tagout Breaker Box Lock for Standard Single and Double Toggles, 493B
- TRADESAFE Circuit Breaker Lockout Device, 3 Pack, 480/600 Volt, Clamp-on Breaker Lock Out Device, OSHA Compliant, Premium Grade, Large
- TRADESAFE Lockout Tagout Locks Set - 10 Red Loto Locks, Lockout Locks Keyed Different, 2 Keys Per Lock, OSHA Compliant Lock Out Tag Out Padlocks, Safety Padlocks for Electrical Lockout Tag Out Kits

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*Product available on Desertcart Hong Kong*
*Store origin: HK*
*Last updated: 2026-03-07*