For professional needs such as small apartments, churches, restrooms and small offices; specifically designed where basic security needs or specific codes must be met, but usage is low to moderate. Outside knob is fixed, entrance by key only; inside knobalways unlocked. 1 piece knob for better security and appearance. Solid brass trim and all metal parts. Wrought brass exposed trim. Pressure cast zinc tubular lock housing. Key removable outside knob for easy cylinder replacement. 3 piece assembly for easy installation. SecureKey technology enables you to re-key your locks in seconds.