9875/9975 Mortise lock device for all types of single or double doors, UL listed for panic exit hardware. Devices are certified to ANSI/BHMA A156.3 2014, Grade 1. Fits stock hollow metal doors with 86 cutout and door stiles as narrow as 4-3/4" (121mm). The 9875 device has a smooth mechanism case and the 9975 device has a grooved case. The mortise lock device is non-handed except when the following device options are used 2 (double cylinder) or SS (signal switch). The 7500 Mortise lock is equipped with a 3/4" (19mm) anti-friction latch bolt which is field reversible without removing the lock from the door. It has a non-handed auxiliary bolt for deadlocking and a faceplate with an adjustable bevel.