MIFAB® Series MI-QXHUB (specify size) heavy duty shielded no hub couplings are manufactured with gaskets made from neoprene (meets the requirements of ASTM C-564) housed inside a Type 304 stainless steel corrugated shield. Four (2" through 4" size), six (5" through 12" size) Type 304 stainless steel clamps tightened with 3/8" Type 305 stainless steel hex head screws surround the shield to provide the sealing force. MI-QXHUB Series Couplings are tested and certified to the ASTM-C1540-2018 and CSA B602 Standards and listed with I.A.P.M.O. The MI-QXHUB are also tested and certified by Intertek Testing Services to the CAN/ULC S102.2-10 “Smoke Test". The MI-QXHUB are tested by IAPMO to comply to the FM 1680-1989 Standard (except for markings).