Flat panel solar collector, flat plate solar collector, high heat efficiency Special Design Flat panel solar collector ,flat plate solar collectorFeatures: 1) When the discrepant temperature of the solar collector and water tank reachesthe ... Tubes Shape: Straight line typeAbsorber Fin: 140 mm, 7pcs, Copper (TP2)Welding method: Ultrasonic weldingSpectrum Absorber Coating: Blue CoatingAbsorptivity : ...