These single or double row units comprise machined outer rings without ribs, needle roller and cage assemblies and removable inner rings. Since the bearings are not self-retaining, the outer ring, needle roller and cage assembly and inner ring can be fitted independently of each other. Needle roller bearings without ribs are X-life bearings. In this design, the raceway surfaces are optimised. This gives higher load carrying capacity and longer rating life.Needle roller bearings without inner ring: Bearings without inner ring have particularly compact radial dimensions. However, they require a shaft raceway that is hardened and ground. The needle roller and cage assembly can be fitted either together with the outer ring or with the shaft. It can also be subsequently slid between the outer ring and shaft. Needle roller bearings with inner ring: Bearings with an inner ring are used if the shaft is not configured as a rolling bearing raceway. The needle roller and cage assembly can be fitted either together with the outer ring or with the inner ring. It can also be subsequently slid between the outer ring and inner ring.