ASI FTNG139-Z11N is a standard size roller lever limit switch with a 17.5mm diameter plastic roller. It features a variable length lever. It is ideal for use in elevator applications. The limit switch is designed with 1 NC and 1 NO removable Snap Action contact that allow for convenient and easy wiring of the contact block. The flame resistant plastic housing has an M20 threaded opening at the bottom and the cover is hinged and flips down for easy access for wiring. The mounting screws are 30 mm apart at the top and bottom of the housing. The heads are held in place by 4 screws. The FTNG139-Z11N limit switch is cULus listed and has a mechanical life greater than 10 million cycles, and an electrical life greater than 150,000 cycles.