They cover a wide dimensional range, have the radial part with full complement of rollers, but there are also versions for high speeds with a reduced dimensional range. The high speed version has a radial cage, mounted in an outer ring: this also functions as a central washer for the axial assembly (this version is able to absorb bidirectional axial stresses, assisted in this by two needle cages and lateral washers spaced apart by an inner ring which generally forms a whole with one of the two washers).
Outer and inner rings and washers are flanged to allow the assembly and eventual adjustment of the rolling unit; they have high precision and rigidity and withstand loads and tilting moments of considerable intensity, they are supplied pre-lubricated with grease and can be lubricated by through an adequate drilling of the outer and inner ring.