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 thermoplastic polyurethane, low-noise operation, low rolling and swivelling resistance, good floor preservation, very high abrasion resistance, chemically bonded for an inseparable connection to the wheel center.