For residential and multi-family hall/closet doors. Both knobs are always unlocked. DOOR THICKNESS: 1-3/8 in to 1-3/4 in LATCH: 1 in x 2-14 in , radius corner faceplate, 7/8 in housing diameter, 1/2 in throw, with Triple-Option square corner and circular corner faceplate. STRIKES: Dual strikes 1-5/8 in x 2-1/4 in , radius corner and square corner, full lip, no box. BACKSET: Dual backset latches, fits either 2-3/8 in or 2-3/4 in backsets.