Rugged,water-proof,vandal-proof keypad with 12 back-lit keys,ideal for indoor or outdoor access ... the front panel way to the edge of the back panel, so the membrane also functions as a ... ;keys:high temperature polycarbonate(stainless steel keys also available);back panel:aluminumLife cycle of keys: >5 million operationsKey travel ... (front panel) IP68 rated indoor or outdoor keypad with back-lit keys