Battery-powered keypad lock with a randomly changing number array every time it's used. Features: Randomly changing number array The key feature of the random keypad lock is that the arrangement of the numbers on the keypad changes randomly each time it's used. Since fingerprints don't remain in the same position, the risk of others finding out your PIN is avoided. Even when changing the PIN, you can easily invalidate the old number and register a new one. Anti-mischief function If the PIN is entered incorrectly four times in a row, the device automatically stops operating for 3 minutes. This ensures reliable security against mischief and theft. Flexible locking/unlocking control (automatic locking) There are two types: the TK4L type, which locks and unlocks by entering the PIN on the keypad, and the TK4LT type, which unlocks by entering the PIN on the keypad and automatically locks when the door is closed. Long-life, highly durable battery-powered Because it has a built-in battery, it is not affected by emergencies such as power outages. It uses a lithium battery (2CR5), and the battery life is very long, lasting more than 3 years when operated 10 times a day. *The battery is old, so it is recommended to replace it with a new one. You can rest assured even in an emergency. Everything in the photos is included. I am not familiar with the detailed specifications, so I may not be able to answer your questions. Please refrain from purchasing if you are particular about details or are overly sensitive, as this is a used item. Please only purchase if you understand that this is a used item, as anything can happen.