BLUEROCK Tools 4" Concrete Core Drill Model 4" Z-1WS Coring Drill Max Drilling Diameter: 4&#034; Rated Voltage: 110V Rated Frequency: 50-60Hz Rated Input Power: 1500W Dual Speed: 2100rpm/950rpm Arbor size is 1 1/4&#034; 7UNC Two-gear rotary speed is designed for drilling different size holes. The drill is fitted with a safety slip clutch <ul class="a-unordered-list a-vertical"> #2 gear (2100rpm) is for smaller drill bits 1&#034;-2&#034; #1 gear (950rpm) is for larger drill bits 2&#034;-4&#034; This unit is designed to be an easy portable type drill for easy hand drilling New improved water hose assembly with metal fittings and hardware for &#034;wet&#034; drilling Collar size is 2 23/64&#034; Drill color is red Bubble level on end of the drill for precision drilling Removable shoulder rest attachment Automatic hold down switch for comfort 2 Wrenches, 3 hex wrenches, 2 spare brushes Adjustable carriage This unit is designed to be portable and able to be used with an included drilling rig.