Stainless Steel. This 12VDC internal surface fixing keypad with doorbell facility from RGL has a zinc alloy electroplated casing and is supplied with PCB conformal coated components. Up to 500 users are allowed and the unit has LED indication, an optional backlight facility and both lock and aux outputs. There are 12 buttons and the keypad accepts a 4 digit pin code.. LED indication. 500 unique users. Internal use. Dual relay