Holdens SupaSeal Limited manufacturers of premium quality high performance double glazed sealed units, also known as Insulating Glass Units (I.G.U). Established for over 80 years, Holdens SupaSeal remains an independent family-owned company whose name is synonymous with quality within the glass industry. Holdens SupaSeal offer a range of high performing glazed units incorporating the latest glass technologies; energy efficiency, self cleaning, solar control, together with warm-edge spacer and argon gas filling