SPA----stainless steel SUS 304 2B for the manifold SPB----Aluminum alloy for the manifold 1. Borosilicate glass according to ISO3585:1991; transmittance of borosilicate glass:0.92.Absorbance of solar selective absorptive coating:0.94; Hemispherical emittance:0.08; Getter according to GB/T9505-1998. 2. Start-up temperature: no more than 25. 3. Start-up time: no longer than 2 minutes under normal sunshine. 4. Low temperature resistance: no breaks at -30. 5. Heat impact resistance: no damage after over 3 time’s alternative impact of cold water below 25 and hot water over 90. 6. Pressure resistance: can withstand 0.6Mpa. 7. Hail resistance: no damage by the impact of 25mm diameter hail.