This pair of school chairs, model Sena, was designed by António Sena da Silva, in colaboration with Gastão Martins Machado and Leonor Álvares de Oliveira, and produced by Móveis Olaio, in Portugal between 1972 and 1988. After 1988 was produced by FOC (Fábrica Osório de Castro) and exported to France and Japan. These chairs were part of long research, that begun in 1962, about the school modules, such as pedagogy, hygiene, economics, aesthetics and mainly ergonomics. These pieces were done to adapt to the human body as well the student positions in a classroom. These pieces could also be stacked on top of each other and dismantled for easy transport to export. This pair is made of beech wood and is in original and good condition.