Groover adds 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 and squeeze the trigger. Groover features a 4 level dial and a hi/low switch providing 8 total heat settings. Includes 2 each 4/32", 6/32" 8/32" and 10/32" flat blades.