High Quality Wheel Bearings and Seals from All Balls. Seals are double lip type to ensure dirt stays out. Bearings are precision high speed manufactured to ABEC3 standards. Chevron SR1-2 Grease is used to keep bearings lubricated and rust free. Rubber seals are used on the bearings for additional protection from water and dirt. Use these bearings and be assured of trouble free riding for years to come.