Wall mount combination lock box is best used for key and access card storage; Large internal cavity allows secure storage for multiple keys Set your own four-digit combination lock box; Reset the combination for thousands of personalized combination code options Lock box features light up dials for better visibility in low light conditions; Dials light up automatically each time the weather cover is opened Lock box designed for installation to a fixed object; Metal body and weather cover for durability 2-7/8 inch (72 millimeter) wide lock body; Internal dimensions: 4-3/16 inch (106 millimeter) height, 2/38 inch (60 millimeter) width, 1 inch (25 millimeter) depth; Replaceable CR2032 Battery (installed)