Tyre: ESD TR polyurethane, dark-grey nonmarking colour, with electrical resistance <10^9 Ω (=<1GOhm), hardness 90 Shore A, with excellent rolling resistance and elasticity and good resistance to wear and tear.
Centre: made of cast aluminium.
Ball bearing bore or bore withour bearings
The housing is obtained by moulding and contains ball bearings series Z. The hub is available also without bearings.