The bearing within your brake drum or wheel hub helps your tires rotate. Keep your car and truck running smoothly with the ABN Wheel Bearing Press Automotive Grease Bearing Tool Kit 1-Pack. This wheel bearing grease packing tool ensures that your hands and workbench do not get covered in grease while working on your car's bearing. Fill the wheel bearing grease press using your bulk grease or grease gun (not included). The lower compartment and blue covering cap will keep your new grease safe from contaminants when not in use. To press out old grease and in new grease, simply place your car bearing onto the grease gun wheel bearing packer and use the white attachment to gently press down. Car wheel bearing tool is designed for car bearings measuring 3 1/2-inch (8.8) in outer diameter. Warning: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm.