1. CE, RoHS certificates; 2. Anti-freezen & pressurized; 3. warranty:5 years for vacuum tubes. Specification: Manifold casing materialAluminum alloyFrame materialAluminum alloyHeader pipe materialCopper diameter:35mm, thickness:1.0mmHeat pipe materialCopper diameter: 8mm, thicknes:0.6mm .consider cover diameter:14mmanti-freeze sizeInsulationRock woolRubber seals and ringsUV stabilized high ...