Mikuni HS42/018-42K 42mm Rubber Flange Adapter Mikuni For Harley-Davidson Mikuni Rubber flange for mounting HSR to Mikuni Shovelhead or other Harley Davidson 2 bolt manifolds For Carbs with 45mm spigots and up to 42mm bore size Has slotted 8.5mm diameter bolt holes for studs wit 70-75mm centre to centre spacing Extra heavy construction with a second sealing ring on the bolt up surface Does not require the use of gaskets or sealant on machine finish surfaces