Rund shape 98mm (3.86 inch) round faceplate, please remember to check the size to match your safe box before you buy. High grade zinc alloy fire keypad with solenoid lock and 2 override keys that is strong, , fire , , provides physical protection against forced entry, and offers a 3 error code locking mode. Installation: Open with 3-8 digital codes that can be programmed and 3 different colors of lights indicating different states. To replace the battery, remove the keypad face by pressing the tab counterclockwise. Our digital keypad security solenoid lock replacement are suitable for home and lockboxes, , hotel , cabinet , slot . If you are not a safe technician or professional locksmith, please do not attempt installation. If you have any questions or difficulties, please contact us and we be happy to help you.