Water barrier is made of EPDM with high quality rubber. Elastic gasket is used by Santoprene from America. It is qualified under ASTM D3652/D3652M-01(2012), ASTM D41, 2-2006a(2013), ASTM D1415-06(2012), ASTM D2137 type A, ASTM D573-2004(2010), GB/T 7762, ASTM D395-14, ASTM D624-00(2012).