Edelbrock heat exchanger part # 15549 is a dual pass/single row design and delivers 20,500 btu/hr. Includes a 3/4" 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 (20"W x 8"H x 2"D). Edelbrock offers a wide selection of Universal Heat Exchangers to work with the E-Force Universal or Enforcer Supercharger systems. Edelbrock heat exchangers offer reliability and durable construction for high performance street applications.