Tailpipe Expander Set For use on all types of tailpipes, mufflers, and exhaust systems. Designed to quickly and easily straighten out clamp dents in mufflers and tailpipes. A simple wrench turn expands the pipe for exhaust system repair and installation. Works with all 1-1/8 to 3-1/2 inner diameter thin-wall pipes. Drop forged, heat-treated. Includes:. Small Expander: 1-1/8 to 1-3/4. Medium Expander: 1-1/2 to 2-1/2. Large Expander: 2-1/8 to 3-1/2. (3) Spare sets of rubber O-rings. Blow Molded Storage Case 5723