This shop chair was manufactured by Thonet around 1900. Marked underneath the seat: "Thonet Austria" and paper label Gebrüder Thonet. Reminiscent of chair no. 17, but smaller and slimmer, designed by Michael Thonet around 1865. This piece has an attribution mark, I am sure that it is completely authentic and take full responsibility for any authenticity issues arising from misattribution