This Solid Chair is by Heinz H. Landes, a German Postmodern artist active in the 1980s. It's made of ten pieces of rebar and a block of concrete: Chicago-based vintage design reseller Carefully Picked has a pair of the chairs for sale. Their video is below. Sitters may be surprised to feel that the rebar has some give:These chairs would make an unpleasing gift for a construction worker who spends their days working these materials, but in 1986 it was suitably titillating for the gallery-going crowd.