This needle roller bearing guides a shaft along a track by means of a single row of needle rollers running against a particularly thick-walled outer ring. The RSTO20 has an outside diameter of 47.0 mm and a net mass of 0.137 kg. It is supplied as an open design without an inner ring, and without axial guidance of the outer ring; the outer ring and the needle roller and cage assembly can be mounted separately. Since the bearing has no sealing, it must be protected against contamination and supplied with lubricant through the surrounding housing design, and the mating shaft surface takes over the function of the inner ring. The open construction and separate mounting of the components allow flexible installation arrangements, while the thick-walled outer ring gives the assembly the load-carrying capacity needed for direct rolling contact along a track surface.