Groovers add extra traction in minutes. Tapered, razor sharp blade grooves fast and easy. To operate, insert a blade into groover, set blade height with a tire depth gauge and set the power level. Triggerless activation by placing the cutting edge against the tire surface and apply pressure to activate rocker switch, built into head, creating instant heat. Includes 2 each 4/32", 6/32", 8/32" and 10/32" flat blades.