1) Metal-glass evacuated tubes with heat pipe provide 10% higher efficiency solar collection than normal all-glass tubes 2) Able to be used in all climates 3) Copper heat pipes for rapid heat transfer 4) Easy plug-in installation for mounting on the roof or at ground level 5) Maintenance free 6) Suitable for mains pressure water (up to 8bar / 116psi) 7) Corrosion resistant silver brazed copper header 8) Frame material: 304 2B grade standard steel 9) Casing material: 304 BA or AB stainless steel 10) Excellent insulator in glass wool 11) Collectors may be connected in series to increase water heating capacity 12) Tubes easily replaced if broken - can be used with broken tubes 13) Ideal for commercial solar water heating applications