ABEC-5 Radial Bearing featuring 52100 High-Carbon Chromium alloy races paired with grade 5 Balls with 90% fill, high-pressure, water-proof grease. Designed specifically bicycle applications, the LLU/LLB seal combination on these bearings utilizes a more protective LLU seal facing outward, towards the elements, to reduce contamination from water or dirt, while the lighter-contact (less seal-drag) LLB seals facing inward keep the grease where it belongs.The Enduro line of bearings are available in High-Carbon Chromium Steel, 440C Stainless Steel, Ceramic-Hybrid and XD-15 with Ceramic or Stainless Balls. Our bearings are always engineered with deep groove races to accommodate the largest balls possible. All of our standard bearings feature dual-lip seals that ride in a micro groove creating a full labyrinth to provide ultimate protection against the elements.Bearing Code: ACB MRA 2437Dimensions: 24mm x 37mm x 7mmABEC: 5Grade: 5Seals: LLBGrease: Kyodo Yushi PS-2Application: Bottom Brackets