... the tank capacity,copper pipe: material purple copper,glass tube: high borosilicate 3.3, thickness: 2.0mm,insulation: rock wool, and import ... full system completely autumatic, you can uae hot water anytime, high efficient,and no-pollution.3. installation: instal full system is ... manual instruction.4.use copper pipe for transfer hot, more high efficient, and water more clear,because no water in tube ...