Called Crystal Glass, is a single or monolithic clear glass with an extremely precise polished on both sides thereof to not distort the image. The most common thickness is 4 mm, 5 mm , 6 mm, 8 mm and 10 mm, 5 mm being the most used as a simple glass, because of its balance of cost, strength and weight. The thermal transmittance of this type of glass is very high, so it is advisable not to install exterior walls, since there is escape us a lot of energy, for it is almost forced to combine in a glass chamber type or Guardian Sun, multiply by 4 to efficiency, 4/10/4 glass being the most used two 4mm crystal glass separated by an air gap of 10 mm and can also combine with other monolithic glasses to suit the client. As brightness is a glass which passes almost 100% of the outer light due to its transparency. You can use this type of glass 8 mm or 10 mm as acoustic, because with these thicknesses will reduce about 34 decibels of outside noise annoying. The crystal glass of 5 mm weighs 12 kgs per square meter workshop in Barcelona PONSICO have glass plates 2100 mm x 1600 mm in stock , to cut to the desired size .