This ergonomic chair was developed in 1992 for schools in the Basel region, made by the Basler Eisenmöbelfabrik Sissach (founded in 1899, now BEMAG).
It's the fanciest school chair we've seen - steel construction, pneumatic cylinder to adjust the seat height, and adjustable back rest. It's in great vintage condition and would be a classy addition to any office.
Very good, minor wear on seat and frame
Sissach / BEMAG
39 x 39 cm (seat), 42 x 42 cm (base), 70 - 84 cm (height, adjustable)