Consisting of two (double glazing) or three (triple glazing) panes of glass separated by a sealed space around its perimeter filled with air or gas. The composition of insulating glazing is custom-made according to the desired objective(s) (decoration, solar control, thermal insulation, sound insulation, protection, etc.). It is coded according to the thickness of the panes and the space between them; for example, 4/6/4 with two clear panes indicates that there will be two 4mm float glass panes separated by 6mm of air.