The lock box adopts anti-rust zinc alloy and heavy-duty steel locking mechanism. This material can protect the lock box from hammering, sawing, prying, etc. This is a durable and reliable key that can be safely hidden.This key lock box with a 4-digit password allows you to set your own combination password, which has 10,000 unique choices to ensure safety and your key security. Tightly sealed and waterproof, durable, can store room keys and keys outside.There are 2 installation options for this key combination lockbox. You can install it on the wall using the attached plugs and screws.The portable key security gym locker provides a spacious internal space, which can accommodate up to 5 room keys; when traveling or on business, you can put the room key, car key or access card in.By using this 4-digit key lock box, you or others can access the key at any time, which is very suitable for daily activities, friends, relatives, family services, emergency entrances, pet sitters and real estate businesses, etc.