Product Name Flat panel solar collector Model YYJ-C01 Type Pressurized manifoild Heating System Thermal (Passive) Connection Type Direct-Plug Recommend region Europe, Middle East, North America, Asia, Oceania Tube number 10 Tubes /15 Tubes/20 Tubes/25tubes/30Tubes Warranty 15 years Certificate Solar keymark , SRCC, CE ,TUV .etc - See more at: http://www.ejaisolar.com/productsd.php?pid=39&tid=7#sthash.pq2fvDzB.dpuf