In-Pila is a complete collective seating program studied and planned to furnish the widest possible use from educational classrooms or conference rooms to waiting rooms. The characteristic design of the seat back where the fastening elements become elements of design should be noted. Attention is also given to the comfort of the chairs making it possible to combine elegance and sturdiness. The geometry of the structure allows the chairs to be perfectly stacked vertically making it easier to store them. Besides the version fixed on 4 legs we propose versions with and without arms, with panic-proof writing tables and the version with chairs mounted on a bar.