Pre-Set drill bit does not need to be changed for different material thickness Screw Length-Gauge recommends the appropriate screw length for material thickness Automatic Depth Control System allows for easy set up for different material thickness' Variable Spaced Bushings allow a variety of positions for the pocket holes Self Adjusting Clamp adjusts automatically to material thickness Repeatable clamp makes multiple pieces quick and easy Built-In Drill Bit collar set up does not need to be changed for different material thickness' Removable Dust Port can be hooked up to a Porter Cable Dust Extractor or standard vacuum Material Capacities: 1/2" to 1-1/2" Pocket Bit Diameter: 3/8" Pilot Bit Diameter: 5/32" Includes: 3" and 6" Square Drive, 3/8" Drill Bit, Drill Bit Collar, Hex Key, (20) 1" screws, (40) 1-1/4" and 1-1/2" screws, clamp