A safe eposit box (sometimes incorrectly called a safety deposit box) is a type of safe usually located in groups inside a bank vault or in the back of a bank or post office. It usually holds things such as valuable gemstones, precious metals, currency, or important documents such as wills or property deeds that a person might feel afraid to leave at home due to fear of theft, fire, flood, tampering or other reasons. In the typical arrangement, a renter pays the bank a fee for the use of the box, which can be opened only with production of the assigned key, the bank's guard key, the proper signature, or perhaps a code of some sort. Additionally, some banks are using biometric dual control security to complement the already increased security procedures.