9875-F/9975-F Fire exit mortise lock devices for all types of single doors up to 4′ x 10′ (1219mm x 3048mm) or 8′ x 10′ (2438mm x 3048mm) double doors installations, UL listed for fire exit hardware; See page 76 for detailed information on UL listed fire exit hardware label and door opening size information. Devices are ANSI A156.3 – 2008 Grade 1. Fits door stiles as narrow as 4 3/4″ (121mm). The 9875-F device has a smooth mechanism case and the 9975-F 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) devices.