... UV coating, 10 years warranty, proved by ISO,SGS Grade A twin-wall hollow polycarbonate frosted plastic sheet Quality guaranteed ... 1) 10 years guarantee 2) 50 micron UV layer coated3) Proved by ISO9001:2008 ... store, hotel, stadium, school, amusement center, hospital, ect. 2) Skylight, lighting for corridors, balcony, passages and subway entries, walkways ...