ITEM SPECIFICS: Item: 8 Bearings. Size: 608-ZZ deep groove ball bearing. Size(inch): 0.3149" x .8661" x 0.2755". Lubrication: Self Lubricated (Already Greased). Shields: 2 Metal. Limiting Speed: 34000. Inner Diameter: 8mm. Outer Diameter: 22mm. Width: 7mm. Approximate Weight (1Pc): 0.018lbs.