Full Ceramic R8-2RS Ball Bearings, the inner diameter is 1/2", outer diameter is1 1/8" and the width is 5/16", Bearing is made of Ceramic.

• Item: R8-2rs Ball Bearing
• Type: Full Ceramic Ball Bearing
• Balls: ZrO2 Ceramic
• Cage: PTFE
• Closures: PTFE Covers (white)
• Inner/outer races: ZrO2 Ceramic
• Size: 1/2" x 1 1/8" x 5/16" inch
• Inner Diameter: 1/2" inch
• Outer Diameter: 1 1/8" inch
• Width: 5/16" inch
• Quantity: One Bearing
• Highest Temperature: 356(degrees fahrenheit) = 180(degrees Celsius)