Bearing Buddy Trailer Wheel Bearing Protectors w/ Visual IndicatorBearing Buddies replace the dust cap in the axle hub, which is filled with grease through the Bearing Buddy. When the wheels are submerged, pressure from the spring-loaded piston keeps the water out! Sold in pairs.Model No. 1980A - Available in Chrome or Stainless Steel FinishFor use with 1.980 inches (50.29 mm) hub bore, Outer Bearing Cone: L-44643, L-44649, L-44640, Outer Bearing Cup (race): L44610Visual Indicator Bearing Buddy Features: Prevents wheel bearing failure; Keeps water and dirt out of hubs and bearings; Eliminates the need for bearing re-packing; Stainless steel or Chrome barrel and components provide maximum corrosion protection; 100% inspected, quality construction; Automatic pressure control feature prevents hub seal damage; Easy installation - instructions included; Sold in PairsHow to Select the Right Bearing Buddy:Pick a genuine Bearing Buddy to match your hub bore. To convert a model number to the hub bore in inches (or dust cap diameter), simply place a decimal point after the first digit in the model number. Model #1980, for example, fits a 1.980" bore hole diameter.How to Determine the right size Bearing Buddy?How often do I need to repack bearing with Bearing Buddy installed? We recommend inspecting your bearings no more than once every 5 years, as long as you maintain the proper grease level in the hubs and install genuine Bearing Buddy units with new bearings and seals. The Bearing Buddy system keeps a steady 3 p.s.i. pressure on the grease inside the hub. With proper maintenance, the hub remains fully greased, eliminating the need for regular bearing repacking. Some customers have shared that their Bearing Buddy units were removed for the first time after 10 to 15 years of use, and the bearings still appeared to be in excellent condition.