1.Glass cover:3.2mm Low-iron tempered Glass,iron oxide less 80PPM,light transmittance 92-93.5% 2.Frame:6063TS Aluminium alloy Blue Sputtering Membrane Solar Flat Collector Product features1.Glass cover:3.2mm Low-iron tempered Glass,iron oxide less 80PPM,light transmittance 92-93.5%.2.Frame:6063TS Aluminium alloy frame,thickness 1.1-1.5mm.3.Absorber:adapted Germany technology,blue sputtering ...