The Irma armchair has the same typology of its precedent, Lierna, which is updated with a tubular burnished steel structure to make it more resistant.

Achille Castiglioni chooses to use a 25mm diameter steel tube in this chair, burnished or stove enameled in black charcoal, white or aluminum. The seat is in nylon coted with leather and its form is designed rigid, as to compel a correct body position during lunch.