ABLOY® PROTEC keys are cut on two different radii, disks are blocked at their position after a quarter turn by the return bars. Return bars also scramble the disks during key exit and hold disks at position to prevent picking and false opening. Disc Steering System guides the key into the lock with no resistance for less key wear. Patented and highly restricted, ABLOY® PROTEC has over 1 billion useable combinations, no code is ever repeated. ABLOY® PROTEC has also proven to have an incredible resistance to physical attack and environmental situations, while being pick proof and bump proof.