RPM Bearing Blaster has an open, flow through design that eliminates back-pressure problems which also permits more efficient elimination of dirt and grit from the bearings being cleaned. This tool uses hand pressure to hold the bearing in place during cleaning which means easier access to the bearings and makes cleaning bearings much quicker. By using hand pressure, you will know for sure the cleaning agent is passing through the bearing and not around it. The Bearing Blaster works with all bearings* with a minimum I.D. of 1/8" (3mm.) and a maximum O.D. of 3/4" (19mm.). Standing at a mere 1-1/8" tall and 1-3/4" in diameter, it will be the smallest, most effective tool in your tool box! No other bearing cleaning method currently available compares to the effectiveness of the RPM Bearing Blaster!