R-720 is an Open Miniature Ball Bearing, R-720 Bearing has an inner diameter of 2mm, R-720 small Bearing outer diameter is 7mm and R-720 Bearing width is 2.8mm, R-720 Bearing is made of Chrome Steel, 52100 is a high carbon, chromium containing low alloy steel, heat treatment and hardening of 52100 alloy steels will get you 60 Rockwell hardness and very common in bearings.

• Item: R-720 Bearing
• Type: Radial Small Bearing
• Closures: Open
• R-720 Dimensions: 2mm x 7mm x 2.8mm
• Size: 2 x 7 x 2.8 mm
• Material: 52100 Chrome Steel
• Bearing Inner Diameter: 2mm
• Bearing Outer Diameter: 7mm
• Bearing Width: 2.8mm
• Standard: Metric
• Quality: Standard Precision
• Quantity: One Bearing