Keep valuables hidden and secure with this electronic wall safe. Easily retrofits in any standard wall with 16" studs. Secures in closets or behind paintings. Easy to install. Lock is electronic with thumb throw latch. User codes: 1 master code 3 to 8 digits. Power supply is 4 AA batteries inserted on inside of safe. Tamper proof feature: minute hold after 4 incorrect tries. Two emergency override keys provided (not needed to open safe). Code can be easily changed with internal reset button. Mounting: secures with 2 pre-drilled holes on each side. External Dimension: 20.67 inches high x 13.78 inches wide x 3.74 inches deep. Internal Dimension: 20.28 inches high x 13.39 inches wide x 3.35 inches deep. Weight: 37 lbs. Color: Cream.