This Angular-Contact ABEC-5 bearing features deep-groove design races, with Grade 10 balls, dual-lip labyrinth (LLB) seals to withstand daily abuse of use and the elements, and to contain the 90% fill Mobilux NGLI 2 high pressure water proof synthetic grease. When properly installed (black seal facing in) and adjusted, Enduro Angular Contact (A/C) bearings engage all of the bearing's balls to spread the force over a larger surface area, decreasing friction, minimizing wear and increasing bearing life.