... 2.offer OEM 3.15years warranty 4.AntifrezzeDetailed Product Description: 1) Inner tank material: SUS304-2B stainless steel, thickness: 0 ... tube. Tubes quantity: 20pcs. Available tubes are 15, 16, 18, 20, 22, 24, 26, 28, 30 and 36pcs, over 15 years ... 8)Hail resistance:25mm. 9)Wind stress:180km/h 10)Freeze protection:-25 degree. 11)Heat preservation:72hours 200L non-pressurized compact solar water heater ...