The Master Lock S3821 Grip Tight™ Plus Circuit Breaker Lockout Device fits Miniature Circuit Breakers (120/240 V). Its lightweight, one-piece design easily and consistently installs without use of tools. The stainless steel thumbscrew and toothed jaw provide a tight grip on the circuit breaker handle so device remains secure. Its compact size allows for locking out vertically and horizontally adjacent breakers. Also suitable for multi-pole breakers and tie-bar toggles.