Model 400 bench designed by harry bertoia, metal legs and wooden slat seat. produced by knoll international, usa, late 50s bibliography: s. Rouland, l. Rouland, knoll furniture 1938-1960, schiffer pub. Ltd, atglen, 2005, p. 112 i have official proof of authenticity such as vintage catalogs, designer records, or other literature sources and take full responsibility for any authenticity issues arising from misattribution