With a wide contact surface. The filter wrench with automatic grip is convenient to use. Because the more force you turn the wrench, the more the grip strengthens, thanks to which you can almost always open the filters! To turn the filter wrench, you can use a 1/2" wrench. T-screwdriver or a 22 mm ring spanner. The filter wrench is made of CrV special steel. With phosphated surface treatment.