... Specification: 2m*1m*70mm/80mm/90mm, 2m*1m flat solar collector, the water can rise to 55°C in the Sun ... corrosion. Operated automatically, stable performance, little maintenance, can stay for nearly 20 years8. Special preservation: Glass wool/ high dense ... panel are simple, efficient design, durable and economical for application of solar water heating system of residential, hotel, school ,commercial ...