... :Using reflective, tinted, patterned, or low-e glass, IGU’s are produced by adhering an aluminum frame ... between two panes of glass using two layers of sealant (butyl rubber sealant ... noise levels and heat transfer even further. Specifications: Available glass types for IGU:Low-E, tinted, reflective, tempered ... 1/8" - 3/4")Aluminum Spacer Width:6,9,12,14,15,16mm (1/4", 11/32", 1/ ...