Prevents wheel bearing failure on boat, snowmobile, ATV, horse, RV and utility Trailers * Keeps Water and dirt out of hubs and bearings * Eliminates bearing repacking, proven in use for over 35 years and billions of miles of service * Long lasting Stainless steel components, Easy to install, Grease level easily checked * 1.980" Diameter - Used on Dexter and most 3,500 lbs Axles for 5 Lug Drums