MIFAB® Series MI-HUB no hub couplings are manufactured with gaskets made from neoprene compound that meets the requirements of ASTM C-564 housed inside a Type 301 stainless steel corrugated shield. Two (2 through 4 in), four (6 through 10 in) or six (12 and 15 in) Type 301 stainless steel clamps tightened with 5/16 in Type 305 stainless steel hex head screws surround the shield to provide the sealing force. MI-HUB Series Couplings are tested and certified to the ASTM-C1277-2009a, CISPI 310-2010 and CSA B602-2016 (File # 247608) Standards and are listed with IAPMO and NSF certified to CISPI 310. Also tested and certified by Intertek Testing Services to CAN/ULC S102.2-07 Smoke Test.