These variable depth circuit breaker mechanisms are designed for installation in custom built enclosures with Square D main or branch circuit protective devices. This mechanism will work with PowerPact M or PowerPact P circuit breakers. This mechanism can be used with 800A 3 pole PowerPact M or 1200A 3 pole PowerPact P circuit breakers. The varible depth mounting range is 10.50 to 18.90 inches. A 9422A operating handle is ordered separately. Handle mechanism must be ordered separately. A 9422AP1 or a 9422AP2 handle mechanisms is normally used Operating mechanism is UL Component Recognized and CSA certified