In this case, metal is the dominant material. The elegantly curved bent tubular steel loop beneath the seat serves as a foot support. The frame rests on a round base plate. The sitting height can be steplessly adjusted with the aid of a gas pressure spring, and the foot support is adjusted to the ideal distance for the user at the same time. All of these considerations form the basis for a multi-functional product suitable for contract as well as private spaces.

https://www.thonet.de/en/all-products/detail/s-123-ph