This 4-digit lock box is built for years of use. The Vault Locks 3210 lock box comes with a lifetime warranty. If you"re still hiding your spare keys under the doormat, it"s time for a better, more secure solution. The Vault Locks 320 key safe is a wall mounted unit that securely holds keys, cards, or anything else you need to put inside. Compact and durable, this key safe will open only when you enter your personalized combination.