... water heater: low price and good quality. low pressure pre-heating solar water heater description: 1, Diameter of vacuum tube: 47mm ... to 60mm13. pressurized system: 0.6MP14, material of support: Aluminum Alloy15, color of support: black16, inclination of frame: 38 to 45 degree17 ... roof 6)Whole system can be used for swimming pool heating system7) CE, ISO9001, CCC, EN12975 certified 8) Competitive price ...