• For residential single and multi-family hall/closet doors • Both knobs always unlocked • 1 piece knob for better appearance • Solid brass trim and all metal parts • 3 piece assembly for easy installation • DUAL OPTION UNIVERSAL: Fits all doors, 2-3/4 or 2-3/8backset; 1-1/8 square corner, 1/4 round corner, or circular drive-in preps • backset; 1-1/8 square corner 1/4 round corner or circular drive-in preps.