HÅG Capisco 8106 office and work chair, designed in 2010 by Peter Opsvik, manufactured by HÅG Norway. The chair supports various sitting positions (upright, sideways, astride...) and is adjustable in every respect, making it one of the most ergonomic office chairs ever.
The frame is made of aluminium. The saddle seat and backrest are covered with grey'Comfort' fabric. Optically this fabric reminds of fine suede, but is very rugged, and it is manufactured without environmentally harmful chemicals.
The condition of the chair is very good, with only slight patina.
Information on dimensions etc. can be found here.