Enduro's ABEC 5 is the next performance step up from the popular ABEC 3 range. By using military level, high precision HRC-64 hardended Grade 5 Chromium Steel Balls, and 52100 High-Carbon Chromium-Alloy mirror polished races. This combination allows Enduro's ABEC 5 bearings to use tolerances twice as tight as ABEC 3, and operate without any noise. The Graphite/Nylon ball retainers allow virtually frictionless movement and provide constant lubrication to maximise the life of the bearing.Key Features: Bearing Code: 7902 (71902)Dimensions: 15mm x 28mm x 7mmABEC: 5Grade: 5Seals: LLBGrease: Kyodo Yushi PS-2Application: Hubs, Bottom BracketsWeight: 15.00g