The Edelbrock Street Rod Muffler has a 3-1/2" diameter and features a totally new chamber style muffler design. This muffler is constructed from a combination of quality 409 and 304 stainless steel. Overall length is 25" with the case measuring 20". Inlet and outlet are sized to accept 2-1/4" tubing. These mufflers were sound tested, performance tested and approved by Roy Brizio for use on his street and custom rod projects.