... collector with solar keymark 1.High efficiency 2.Imported from Germany 3.Emissivity is only 5% Roof type flat ... Absorbing Coat, Gathering Energy WisdomBluetec heat absorbing board, imported from Germany, with magnetron sputtering technology. The surface is coated with ... high thermal efficiency.Top Level Heat Efficiency, Enjoy Warmth from SunshineSolar absorption rate reaches 95%, emissivity is only 5 ...