Abloy high security deadbolt lock uses key only on one side and has a thumb turn on the other side which can be left in the locked or unlocked position using the key. This lock has two cylinders; one for each side of the door.
Abloy locks are the most secure locks available. The locks cannot be picked open and the keys cannot be copied except by BC Site Service. They are used by banks, government agencies, and facilities requiring high security.
Deadbolt Installation Instructions: