Vacuum Tube Solar water heater: CE certified, high efficiency, TIG welding, easy installation, reliable quality, ... certified, high efficiency, TIG welding, easy installation, reliable quality Solar Water Heater Vacuum Tube: Dia. 47/1500, Dia. 58/1500, Dia. 58/1800 ... , Dia. 70/2000;Vacuum tube qnty.: 12pcs, 15pcs, 18pcs, 20pcs, 24pcs, 30pcs, 60pcs, 120pcs;Inner ...