1, Three layers vacuum tube 2, Copper heat pipes built in 3, Rock woll insulation 4, SRCC,Solar Keymark,CE,ISO red Solar Collector With Heat Pipe 1. Spcification of solar collector out casing: aluminium alloy inner manifold: red copper insulation layer:rock wool/polyurethane foam vacuum tube: 58*1800mm, ALN/AIN-SS/CU 1.6mm thickness heat pipe: red copper, anti-frizen, 1700mm length frame: ...