##Enduro ABEC3 6805 Wheel Bearing 25x37x7 (Single) The Enduro ABEC 3 6805 Cartridge Bearing 25x37x7 is labyrinth sealed with two NBR 70, low-contact, low-friction seals, which ride in a groove machined into the bearing. High precision, Grade 10 chromium steel balls are within 10/1,000,000″ round, twice as round as the industry standard. These precision balls ride in a 52100 high carbon chromium alloy race, hardened to R-62 to make them extremely tough and durable. Mirror finish polishing of the races creates ABEC-3 precision and noiseless movement.