The collector perform high absorptivity ,low emission rate ,well-structured,reasonable designed and high thermal efficiency.. Feature : ... copper coated with black chromium.2.Optical performance:absorption>96%,emission rate<10%3.Header tube/Calandria:TP2>99.85%,width ... .7mm, width of Calandria is 0.5mm.4.Glass Cover:Low-iron tempered glass has more than 92% transmittance,with width ...