... hours.7. Optional accessories: assistant tank, electrical heater.8. 5 years warranty. MaterialEvacuated tubeHigh borosilicate glass, with aluminum absorption layer ... Rate≥0.95±0 ≤0.20±0.02Vacuum Tightness P≤5.0*0.0001PaIdle sunny property parameres Y=220-260./ ... Weight 87KGS87KGSCertifications Solar Keymark, SRCC, SGS, CE, ISO9001Warranty 5 years5 years passive low pressure roof top Solar water heater ...