... .Anti-freezen & pressurized 3.10 years warranty Solar water heater frame Material of Model:1.the heater pipe ... capacity: 150L,200L,250L,300L,400L,500L,600L,700L,800L............solar water collector1) Reliable, efficient, twin-glass evacuated tubes2) Red ... heating,swimming pool, heater floor...7.anti-freeze:using the anti-freezing liquid as the medium and the controller has anti-freezing function Solar ...