Designed for fast, easy lock setup and programming, the Master Lock® 1566 administration key works with the Master Lock® 3685 electronic built-in locker lock and Master Lock® 3681 ADA compliant electronic built-in locker lock with Bluetooth® fob. The key's micro USB connection is inserted into the bottom of the lock and puts it into settings mode, allowing staff to quickly open locks, clear/reset lock codes, and modify lock settings. The 1566 administration key for electronic built-in locker locks can be programmed with thousands of codes and used with new or existing 3685 and 3681 locks. Master Lock® Administration Key, For Use With: 3685 and 3681 Electronic Built-In Locker Locks, Black, 3-3/4 in H x 1-3/4 in W