There are three options. Either emergency battery contacts, backup key or the batteries are installed on the outside of the door. This Chubbsafe includes contacts for a 9v battery hidden behind the keypad while these electronic lock safes all include a backup key.

The floor clearance is 68mm and this is from the bottom of the safe to the bottom of the door.

Here is the Chubbsafes Earth User Guide which should be able to assist you. If you require any further help please feel free to call us on the number above.