The 65965 is a 120/277V clamp-on circuit breaker lockout designed to work on an extremely wide range of single-pole and internal-trip multi-pole breakers. It is constructed from rugged polypropylene and impact-modified nylon, providing durability in demanding industrial environments. The lockout uses a thumbscrew to clamp securely onto the switch tongue, with a cover that pulls over the thumbscrew and locks in place to prevent loosening. The new blade design provides a tighter grip with less torque required on the thumbscrew, and detachable cleats (included) expand the range of applicable breakers. It accepts lock shackles up to 9/32" in diameter. This lockout is ideal for lockout/tagout (LOTO) procedures in electrical maintenance and safety applications where preventing accidental breaker operation is critical.