... tube solar heater with SOLAR KEYMARK,ISO,CE,SGS Copper coiler inside of tank could bear high hydraulic pressure water vaccum tube solar ... : polyurethane frothing, δ50mmVacuum tube: tri-elements coating, 58×1800mmAccessories: water auto-feeding tank, electrical heaterLogo ... water inside of tank, consumer will enjoy fresh and high hydraulic hot water out from the coiler. vaccum tube solar water heater ...