... , durable, convenient, 2.8 years warranty 3. offer sample solar water heater 1.environment protecting, economical, durable, convenient, 2.8 years warranty ... .6mm;3.insulation: polyurethane foam, thickness:55mm;4.vacuum tube: high borosilicate 3.3,size:47mm*1500mm,58mm*1800mm;5.bracket ... ;9.long-life: 15years;More details pls contact us anytime. solar watet heater