Bayer group is one of the leading inernational chemistry and pharmacy enterprices. As an important member of Bayer global polycarbonate(PC) panel system, Bayer Gangyi Co., Ltd. has taken the resposibility to offer top quality engineering plastic-PC panel to customers.Our polucarbonate sheets are all made of polycarbonate rsin produced by Bayer AG and we have the following warranty: 1.The change of Yellowness Index (?YI) should be less than 10 from initial value within the first ten years(when tested in accordance with DIN6167,or ASTM D1925). 2.The decreace of Ligh Transmission (?LT): for transparent sheet, ?LT should decrease by less than 6% from initial value within the first ten years(When tested in accordance with DIN 5306 pt. or ASTM D1003-1995).