Our 6mm twinwall polycarbonate offers high impact resistance, excellent heat retention and 80% light transmission. Avoid expensive shipping and crating charges by ordering these Easy Ship 2ft Wide Twinwall Polycarbonate Panels that ship via Standard Ground Service. ThermaGlas Multi-wall Polycarbonate Sheet is designed and engineered specifically for commercial greenhouse use. ThermaGlas offers 99.5% UV protection. The multiwall design and light weight of the sheet enables a reduction in the cost of the supporting structure. Shatterproof polycarbonate coupled with integrated UV resistant co-extruded layer yields long service periods backed up by a 10 year limited warranty. The cellular multi-layer structure reduces heating costs in winter while minimizing excessive heat in summer. A special coating on the bottom side eliminates condensation dripping. ThermaGlas blocks ultraviolet rays that burn plants and living tissues, and transmits only beneficial radiation.