Bi-Metal, Hole Saw Door Lock Installation Kit, Can Be Used On Both Wood & Metal Doors, Kit Includes 1" & 2-1/8" Bi-Metal Hole Saws, Arbor, Arbor Adapter, 2 Adjustable Bushings & Drill Guide, Alignment Window & Taller Bushings Deliver Accurate Height Placement & Straight Drilling, Adjustable Bushings Accept Both Standard Backsets & Door Thickness, Utilizes C-Clamp Design For Tool Free Clamping.