... warranty 3,Delievery 7-10days 4,High Quanlity&Reasonable Price vacuum tube solar water heater Certification:Have passed SRCC,CE,ISO9001:2000,CCC ... heat preservation5) Specification of vacuum tube Absorption rate: ≥93%,thermal radiation rate:≤6% Temperature when ecposed to sun without water:250 degree ,2 ... -243.402420032/76SP470-1800/58-304.323025026/63 colour steel vacuum tube solar water heater