For hall and closet doors, all interior doors where a simple latch is all that is required. Both knobs always free, no locking mechanism. All metal components. Solid steel latch assembly. Seamless one piece knob for extra strength. Easy installation. Square spindle for right or left handed installations. Fixed 2-3/4 in Backset Square Corner Latch, radius corner or drive-in applications, includes both T-Strike and ASA Strike.