3pc Exhaust Tail Pipe Muffler Expander Spreader Tool Set Forged 1-1/8" to 3-1/16" Works with all 1-1/8" to 3-1/16" ID. thin wall pipes The use of Tailpipe Expander tools is best used on thin wall piping aided with heat to provide the best uniformity and ease of the expansion. Small Expander: 1-1/8" to 1-3/4" (29mm - 44mm) Medium Expander: 1-1/2" to 2-1/2" (38mm - 64mm) Large Expander: 2-1/8" to 3" (54mm - 89mm)