... CE,SGS - Automatically controlled - Highly efficient insulation with polyurethane low pressure olar water heaterMaterial:Inner tank: stainless steel SUS304/2B, δ0.41mmOuter tank ... , δ50mmVacuum tube: AL/N coating, 47×1500/58×1800mmAccessories: water auto-feeding tank, electrical heaterLogo: OEM, color printing/stickerCapacity: 120 ... life, can be used as long as 15 years low pressure solar water heater