1 rotating 4-branch base without castors, finished in brilliant-chromed steel. - 1 rotating 4-branch base without castors, in grained anthracite-finish steel. - 1 rotating, height-adjustable 5-branch base on castors, in polished aluminium. - 1 rotating, height-adjustable 5-branch base on castors, in grained black-finish aluminium. For both chairs and bridges equipped with a 5-branch base on castors, the minimum and maximum heights and seat heights are indicated beneath each item.