Edelbrock heat exchanger part #15549 is a dual pass/single row design and delivers 20,500 btu/hr Includes a 3/4in. barbed inlet and outlet for plumbing, along with M6x1.0 threaded bungs for mounting and includes brackets. Heat exchanger part #is a Dual Pass/Single Row Universal Heat Exchanger with the following dimensions (20in. W x 8in. H x 2in. D). Edelbrock offers a wide selection of Universal Heat Exchangers to work with the Edelbrock Universal or Enforcer Supercharger systems. Edelbrock heat exchangers offer reliability and durable construction for high Performance's street applications.