Specification:
1. Manifold (interior): red copper;
2. Manifold (exterior): aluminum alloy;
3. Insulation: rock wool;
4. Glass tube dimensions: 47mm x 1.5m;
5. Coating of vacuum tube: ALN/AIN-SS/CU OR AL-N-AL;
6. Heat preservation: 72 hrs;
7. Hail resistance: 25mm;
8. Heat pipe : anti-freezing > -35 degree