1.Certificate: SRCC, Solar keymark ,EN12975,ISO,SGS,CE,CCC 2.Lifetime:15years 3.Deliverly time:10-15days 4.Best performance solar energy vacuum tube collectorLatest solar keymark list:SCM12-58/1800-02SCM15-58/1800-02SCM20-58/1800-02SCM25-58/1800-02SCM30-58/1800-02better efficiency,better priceManifold(exterior):aluminum alloyGlass tube dimensions:58mmX1.8mDaily efficiency:>55%Hail resistance: ...