... wind and hail well 2.CE,ISO,SRCC approved 3.can endure 0.6Mpa high pressure 4.high efficiency,stable Heat Pipe Tube Solar ... Leading Time: 3~7 WorkdaysMaterial:heat pipe material: borosilicate glass,with a red copper pipe in it.heat pipe QTY:15pcs ... :0-90 degreeHail resistance:25mm.Wind stress:180km/hFreeze protection:-25 degree. very popular vacuum tube solar Collector (with CE, RoHS, CCC SGS ISO9001