MF44 PHATY Ice Screws are made of high quality Zinc treated steel, that cut through ice, while evacuating snow when riding on snow filled lakes or trails. This screw is intented to be installed in tires without going through the Liner. Select the appropriate size for your tire knobs. These can be fitted on Small 50cc bikes, Enduro's, Motocross, ATV's for snow plowing, ATV, for forest rides and fields, UTV's, even Plowing Side-By-Side Utility Vehicles. Sharp Edges to cut through Ice. NO NEED TO SHARPEN