Secco’s fixed windows are available in a choice of four materials including Galvanized Steel, Stainless Steel, Corten Steel and Brass OS2 system has been studied, designed and made in order to provide historical and monumental buildings with door and window frames that could visually recall those used from mid 19th to mid 20th century (the typical iron windows. OS2 system is equipped with a 47mm lateral and a 62mm central section, made with thermal break profiles - integrated with a complete range of system accessories - allowing for a wider range of openings.