... , thickness: 50mm, 55mm5.working pressure: 0.6Mpa-0.8Mpa6.Electrical heater: 1500w, 2000w, 3000w7.preservation hours: 72hours solar collector:1.tube ... : 1.6mm aluminum5.bracket material: 1.5mm galvanized plate/aluminum6.heater pipe material: 1.2mm thick copper7.insulation layer: polyurethane8.low ...