The BikeMaster Gear Leverage Oil Filter Wrench removes all oil filters from 2-1/2 in. to 4 in. diameter. Its unique design uses gear leverage to clamp the body of the oil filter so the gears can work forward and reverse for removal and installation. It can be used with 1/2 in. drive ratchets or 21mm wrenches and features quality steel construction with black-oxide finish for long tool life.