The Master Lock S3822 Grip Tight™ Plus Circuit Breaker Lockout Device fits Molded Case Circuit Breakers (480/600 V). Its lightweight, one-piece design easily and consistently installs without use of tools. The stainless steel thumbscrew and curved blade provide a tight grip on the circuit breaker handle so device remains secure. The fixed cleat provides added physical blocking to prevent switch movement into "on" position. Compatible with a wide variety of circuit breaker handle shapes and sizes.