Tuff Stuff V0426T Satin Chrome US26D Always Locked Vestibule Storeroom Commercial Cylindrical Ball Knob Lock Set Lockset. Schlage SC1 Keyway 3 keys. 2-3/8" and 2-3/4" backset Included (Backset is all metal!!! as can be seen in picture), interior knob turns free, key outside, Tubular Type Construction, For Use On Interior Or Exterior Wood Or Metal Doors, 1-3/8" To 1-3/4" Thick. Finish: Satin Chrome US26D. Type: Commercial. Grade: 3. Function: Storeroom. Keyed Different. Keyway: SC1. Adjustable backset. 5 pin solid brass cylinder. Internal mechanism heavy gauge cold rolled steel. Positive push and turn button locking mechanism. 3" threaded rosette outside. Panic proof mechanism. Concealed mounting screws.