... quality, good finish. The following are the features of our vacuum tube solar water heater:CE certified, high efficiency, reliable quality, inner tank TIG ... welding, super stainless steel, easy installation, competitive price.Vacuum Tube: Dia. 47/1500, Dia. 58/1500, Dia. 58/1800 ... , Dia. 70/2000;Vacuum tube qnty.: 12pcs, 15pcs, 18pcs, 20pcs, 24pcs, 30pcs, 60pcs, ...