This website is dedicated for snowmobile Bearing, the most common snowmobile ball Bearing sizes are 6004-2RS, 6204-2RS and 6205-2RS, please browse the site for any other sizes. Most snowmobile Bearing are rubber sealed and lubricated with grease, you can always remove the seals, relubricate the Bearing with grease then put the seals back again. Other snowmobile Bearing design are available, like the ceramic hybrid ones and even the full ceramic.