* Copper fin of selective black painting surface.
   (or Aluminium fin with black painting)
* Absorptivity: 94%-96% Emission: 20%-30%;
* Fin standard dimension:
* Copper: 1840 x 125 x 0.15 mm(Lx W x H)
 Aluminium: 1840mm x 125mm x 0.35mm(Lx W x H);
* Copper tube standard dimension:
* Riser tube: 1880 x 10mm, ( length x OD) thickness 0.45mm.
* Header tube: 1060m x 22mm(or 25mm) x 0.6mm(thickness)