Blue Greenhouse polyethylene film with anti-uv 1,ISO 9001:2008 2,Good quality and good service ... lift : 1 year ,2 years , 3 years ,4 years3, Anti-UV; Anti-dew, anti-dropping 4,Two layer or four layer ... .5, daytime can get more kind sun ; nighttime can protect greenhouse warm Tips : 1, if you buy ...