

🔐 Lock in safety, unlock peace of mind.
The Master Lock 493B Grip Tight™ Circuit Breaker Lockout is a compact, hardened steel device engineered for secure electrical lockout on standard single and double toggle breakers. Its slim profile allows side-by-side installations, making it an essential safety tool for professionals seeking reliable, fast, and durable lockout solutions.








| ASIN | B004J173I8 |
| Best Sellers Rank | 97,748 in DIY & Tools ( See Top 100 in DIY & Tools ) 101 in Circuit Breakers 31,439 in Hardware |
| Brand | Master Lock |
| Customer Reviews | 4.6 4.6 out of 5 stars (1,237) |
| Date First Available | 10 Dec. 2011 |
| Item Weight | 50 g |
| Item model number | 493 |
| Manufacturer | Master Lock |
| Manufacturer part number | 493B |
| Model | Electrical Lockout Device |
| Product Dimensions | 3.81 x 21.34 x 21.59 cm; 50 g |
| Voltage | 240 Volts |
S**S
Isolation lock off device
Required to lock off mob isolator. Better designed mcb with locking capability would be better
A**R
Sturdy
Good price to add to my kit
L**E
Quick and easy
Needed for MCCB’s
P**S
Not for MCB's
Whilst this seems to be able to get a very sturdy grip onto the switch of an MCB, due to the curve of the MCB this does not sit flush and as such gives enough leverage that it can be pulled off the MCB switch. I haven't marked it down as I don't feel this is designed for MCB's but for circuit breakers with flat switch surfaces. Just be aware when buying, NOT FOR CURVE FACED MCB's
H**L
Recommended
Easy to use and good quality
E**A
Me parece de buena calidad y robusto. un poco caro pero contento con la compra
P**E
Good breaker lock like the snug fit
A**Z
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.
D**N
Works extremely well . Was impressed . Would buy it again .
F**C
Sirve para interruptores pequeños, no para interruptores de potencia como lo que yo necesito. Tiene la presilla muy pequeña y no le entra la palanca del interruptores, debería ser de mayor tamaño y con la boca más grande y profunda. No especifican las medidas de la boca para saber si te sirve para lo que necesitas.
Trustpilot
2 weeks ago
1 month ago