... price, a full range of Product Certification separated pressurized solar water heater1 Crystal inner tanker = 1.2mm-2.5mm thick ... heat pipe collector : no water in the tub ,prevent freezing and dirt.II flat solar collector: whole copper pipe,looks ... a cold enviorment. 6 Static water ,cleaner! Quick heat transfer.separated pressurized solar water heaterMain functions1.Display clock and weekday2 ...