This virtually indestructible stainless steel keypad reader is designed to integrate into any access control system, using 26-bit Wiegand format. Solid state, piezoelectric switch technology assures superior performance in even the most extreme environment. The 3 x 4 style keypad features laser etched numbers for years of use. With overall dimensions of 13 cm h x 8.6 cm w x 1.1 cm d (5 1/8 x 3 3/8 x 7/16 in), it can be mounted to a single gang box or surface mount. Field selectable 5 V or 12 V input voltage.