GOOD MATERIAL : The electric coded lock ia m ade of ABS material, strong, precision, safe and durable.The locks have a sleek modern design brief appearance, exquisite workmanship. EASY TO USE : Touch keypad lock use the digital touchscreen numeric keypad to enter a password faster than you can turn a key. The shaft of size M lock is 20mm/0.79inch, it suit to Install in steel or thin wood door which thickness is within 14mm FACTORY STATE: Management password: 1234, default home mode, When the green is unlocked, the indicator light will be on, and if the password is wrong, it will sound. WIDELY USE: Applicable to agent, school, spa/sauna bath center, swimming pool, gymnasium,golf course, supermarket, hotel, company, factory, household, business clue etc. SERVICE: If you encounter a problem in using the lock, you can take a video and contact our customer service, and we will feedback you the reason and solution. If the product is damaged when you received, you can contact customer service for a refund or exchange. Your satisfaction is our greatest pursuit, wish you a happy shopping.Specification: Material: ABS Battery: 3V button battery (CR2032) (Not included) Length of the shaft: M: 20mm/0.79inch, L: 30mm/1.18inch The shaft of size M lock is 20mm/0.79inch, it suit to Install in steel or thin wood door, the thickness of door is within 14mm; The shaft of size L lock is 30mm/1.18inch, it suit to install in wooden door, generally available in thicknesses of 15 to 23 mm door.