For use with grease guns, the design incorporates grease nipple at one end which easilyadapts to the grease gun coupler. For bearings in cars, boats, trailers, 4WDs etc with a minimum inner diameter of 12mm(1/2 inch ) to a maximum outer diameter of 125mm (5 inch ) and height from 6mm (1/4 inch ) to 50mm(2 inch ).