... , 0.31mm thickness. Frame: Galvanized steel, 1.5mm thickness. Insulation: Polyurethane frothing, 50mm thickness. Vacuum tube: Tri-elements coating, ... 58mm×18m.Accessories: Water auto-feeding tank, electrical heater. Copper coiler: For heating exchanging, Ø12mm×30m, inside of water ... tank is 360mm, outer tank is 470mm The interval between tubes: 75mmMinimun order quantity: can be one set Features:1) ...