Key lock box is best used for secure storage of house keys, key fobs, and access cards; removable shackle fits most ball, biscuit, and tulip door knob styles.Note: Measure your door's backset, cross bore and thickness to ensure you find the right fit.Note: Measure your door's backset, cross bore and thickness to ensure you find the right fit. Large easy to read light up dials for better visibility in low light conditions; Dials light up automatically each time the weather cover is opened; Set your own four-digit combination for thousands of personalized combination code options For indoor and outdoor use; key lock box is constructed with a metal body for durability and weather cover to protect combination dials SPECIFICATIONS: External Dimensions: 7in (177.8) H x 2.875 in (72 mm) W X 2.06 in (52.50 5mm) D Internal Dimensions: 4.188 in (106.37 mm) H x 2.375 in (60mm) W x 1in (25mm) D Shackle Length: 1.68 in (42.87mm) Shackle Width: 1.406 in (35.71mm) Shackle Diameter: .375 in (9.52mm)