This needle roller bearing carries a single row of needle rollers running in a particularly thick-walled outer ring, without an inner ring, giving an outside diameter of 52.0 mm and a net mass of 0.155 kg. The outer ring is not axially guided, and the design is open, without sealing. The inner ring, outer ring and needle roller and cage assembly can be mounted separately. The absence of axial guidance on the outer ring allows the bearing to roll along a shaft or track surface, taking radial load only, with the mounting design determining the running surface. Since it is supplied without sealing, the mounting arrangement must provide its own contamination protection, and lubrication has to be applied and maintained externally, matching the operating conditions of the surface on which the roller runs.