Full Ceramic R188 Ball Bearings, the inner diameter is 1/4", outer diameter is 1/2" and the width is 3/16", this is a popular size that could be used in many applications, Bearing is made of Ceramic.

• Item: R188 Ball bearings
• Type: Full Ceramic Ball bearings
• Cage: PTFE
• Closures: Open
• Balls: ZrO2 Ceramic
• Inner/outer races: ZrO2 Ceramic
• Size: 1/4" x 1/2" x 3/16" inch
• Inner Diameter: 1/4" inch
• Outer Diameter: 1/2" inch
• Width: 3/16" inch
• Quantity: One Bearing
• Highest Temperature: 356 (degrees fahrenheit) = 180 (degrees Celsius)