This listing is for 2 piece/s.Deep groove ball bearings are versatile self-retaining bearings with solid outer rings inner rings and ball and cage assemblies. These products which are of simple design robust in operation and easy to maintain are available in single and double row designs and in open and sealed variants. Due to the manufacturing processes used open bearings can have turned recesses in the outer ring for seals or shields. Due to their low frictional torque deep groove ball bearings are suitable for high speeds. Specifications Inner Diameter: 40mm Outer Diameter: 80mm Width: 18mm Features Quiet operation and reduced starting torque Multiple greasing / lubricating options Minimal service or maintenance requirements