Trailer Wheel Bearing Protectors. Fit 1.980" opening. Works like the regular Bearing Buddy, but has new exclusive Auto Check visual lubricant level and pressure indicator. When the hub is full of grease, the blue Auto Check ring rests about 1/8" outward from the steel retaining ring. A spring loaded piston behind the Auto Check ring pushes against the grease which generates pressure inside the hub to keep water out, thus offering true bearing protection. 1980A-SS is made from Stainless Steel. 1 pair.