MIFAB Series MI-XHUB heavy duty shielded no hub couplings are manufactured with gaskets made from an elastomeric compound that meets requirements of ASTM C-564 housed inside a Type 301 stainless steel corrugated shield. Four (2 in through 4 in size), six (5 in through 12 in size) Type 301 stainless steel clamps tightened with 3/8 in Type 305 stainless steel hex head screws surround the shield to provide the sealing force. MI-XHUB Series of no hub couplings are tested and certified to the ASTM C1540-09a and FM 1680-1989 Standards and are listed with IAPMO. Also tested and certified by Intertek Testing Services to CAN/ULC S102.2-10 Smoke Test.