This variable depth mechanism is used with Square D circuit breakers. It is designed for installation in a custom built control enclosure where main or branch circuit protective devices are required. All circuit breaker operating mechanisms are suitable for either right or left hand flange mounting and are convertible on the job. This mechanism is for a 2 or 3 pole FAL, FCL or FHL circuit breaker with a 100A frame size. The variable depth mounting range is 5.38 to 17.75 inches. A 9422A1 handle mechanism is is included with this mechanism. Operating mechanism is UL Component Recognized and CSA certified