All metal construction and large ½” (13mm) keyed chuck for a heavy-duty professional drilling application Infinite angle adjustments between 0° and 60° for drilling. MAKE SURE BOTH KNOB AND HANDLE ARE PROPERLY TIGHTENED BEFORE USE. Included optional non-slip base pads prevent movement and protect the workpiece. INSTALLING SLIP PADS HIGHLY RECOMMENDED TO PREVENT MOVEMENT. Dual Spring Design Increases balance and control while drilling Built in V-groove channel holds and centers round stock for drilling Independent Depth Stop has own guide bar to prevent interference with springs Included centering pins and disk allow for multiple centering options Extruded aluminum guide head with brass bushings for more control and less play Guide head has lock feature to hold in place when changing bits or setting depth Large rubber coated handle adds extra control while drilling