Swivelling in steel plate pressed, pivoting on 2 ball-bearing races, protection of the upper crown by a black plastic dust cap,
thickness of the plate: 3 mm,
thickeness of the cap: 3 mm,
protective white zinc coating.
Wheel body in Pantone 298c color polyamide, Ral 7011 color tread in non-marking elastic rubber dipped on the body, waterproof precision ball-bearing equipped of polyamide thread guard.