... :0.6Mpa 5.Made in China solar water heating systemHeat pipe solar collector, solar collector, solar thermal panel, solar water heater system, 1) Collector channel ... Hail resistance: 25mmModel typeXianke XKPC58-15/20/25constructionVacuum tube solar collectorno. of collector pipes15,20,25tube diameter(OD)58mmpanel area ... and aluminium alloy manifold with rock wool insulation solar energy heating system