Major HIT-444 Drillmaster Kit -DrillMaster, Brad Pt, Multi-Spur, Latch/Strike Marker, Adapter & More Backset Can Be Changed From 2-3/8" To 2-3/4" With A Turn Of A Knob Interchangeable Adapters Allow The Use Of Auger Bits, Multi Spur Bits, Or Hole Saws Multi-Spur Guide Is Removable To Allow The Use Of Hole Saws For Steel Door Installation. Good For Steel Doors, Jaws Are Soft-Padded To Protect Door Surface