ABEC RATING: ABEC1Ball Diameter: 3.969Ball Grade: 10Ball Material: AISI 52100 Chrome SteelNumber Of Balls: 7Bearing Material: AISI 52100 Chrome Steel# Of Shields: 2Inside Diameter: 8mmOutside Diameter: 22mmWidth: 7mmBasic Load: 1370 NDynamic Load: 3300 NWorking Temperature: -20 to 120 CRPM w/ Grease: 33,000RPM w/ Oil: 39,000Chrome steel ball bearing for durability and resistance to deformity under heavy loads. There are a total of 7 balls of grade 10. The shield protects the working parts of the bearing that can reduce lifespan and the ball bearing speed. The ball diameters are 3.969. There are a total of 2 shields in this bearing.