R3 – A triple glazed sound reducing unit. Glass construction from outside to inside is 8H-Tg16Ar-4HT-Tg18Ar-33.2SiT. The outer pane is a 8mm toughened glass with a 16mm warm TGI spacer filled with inert argon gas. You will also find a 4mm toughened glass with a low emission coating. The 6.8mm internal pane is an anti-burglary class of laminate 33.2 (class P2A, EN 356,1(B)1 wg EN 12600), complete with a low emission coating and a sound proof film. This glazing unit produces a U-Value of 0.81W/m²K.