This product is designed for use on a boat's exhaust system. Three shell cores, all made on a U-180 core machine, are assembled and placed in a 12x28 mold that is made on our squeezer line. Poured in class 30 gray iron this is one of the larger castings poured on our squeezer line and the mold takes two people to put onto the conveyor. Casting tolerances required by our customer are 1/64" - 2/32" depending on the wall. Before shipment, this casting goes through a visual inspection and brinell hardness test. The casting is later pressure tested by the customer.