Made of pressed steel, with double ball bearing in the swivel head, ball protection by the special top plate and ball disc design. The special Blickle dynamic riveting process of the swivel head results in minimal swivel head play and smooth rolling characteristics with an increased service life achieved by the work hardening of the ball race grooves. Bolted wheel axle. Zinc-plated, blue-passivated, Cr6-free. Made of high-quality, reaction-injected polyurethane-elastomer Blickle Softhane®, very high operational comfort through the especially thick, elastic tread, low-noise operation, low rolling resistance, very good floor preservation, very high abrasion resistance, high cut and tear propagation resistance, very good chemical connection with the wheel center.