Iron stair with open riser.

Double load-bearing running structure outside steps, made of steel.

Structure painted with micaceous iron glaze , 609.0402 finish, steel grey.

Patented tread with durmast solid wood slats and natural oiled finish with empty/full effect applied to rectangular steps and full/full effect with stainless steel outilnes applied to landings and fan steps-design by Perusko-Sartori.

Tread fixed with no visible screws.