This listing is for 4 piece/s.Single row deep groove ball bearings are the most widely used roller bearing type in the world due to their versatility and overall performance. They are characterized by having deep raceway grooves in which the inner and outer rings have circular arcs of slightly larger radius than that of the balls. They also have non-separable rings. Features Excellent for high speeds Good radial load capacity Acceptable axial load capacity in both directions Have low torque capacity at start-up and running speeds Can operate with low noise Require little maintenance Specifications Inside Diameter: 30mm Outside Diameter: 55mm Ball Bearing Type: Deep Groove Race Width: 13mm End Type: Sealed Number of Rows: 1 Static Load Rating: 8.3kN Material: Steel Cage Material: Pressed Steel Race Type: Plain Dynamic Load Rating: 13.2kN Bore Type: Parallel