Feature: 1. Pipe Expansion Kit: The expander tool provides the handy collets and expander required to stretch tailpipes before making tight seals to pipes with smaller diameters. 2. Practical in Use: Expanding your tailpipe increases exhaust volume, which increases vehicle RPM to give you more power for your engine. 3. Wide Expanding Range: The exhaust pipe stretcher offers expansion range from 1‑5/8in to 4‑1/4in. Includes steel expander 1 5/8in ‑ 2in Collet, 2in ‑ 2 1/2in Collet, 2 3/8in‑ 4 1/4in Collet. 4. Easy Operation: Choose the proper collet, clamp the pipe, and then expand the pipe operation. Use a 1/2in or 3/4in impact wrench (not included) to save more effort. 5. Material: Made of aerospace grade 6061 aluminum while the expander utilizes Tempered 40CR alloy structural steel, ensuring rugged rigidity over an extended service life. Specification: Item Type: Exhaust Pipe Expander ToolMaterial: Aluminum + alloy steel .Specification: Expanding Range 1-5/8in to 4-1/4in Use To Expand Exhaust Pipes Drive Expanding Tool 28mm/1.10in Small Steel Collet 1 5/8in - 1 7/8in Large Steel Collet 2in - 2 1/2in Collet 2 3/8in - 4 1/4in Wide Expanding Range: The exhaust pipe stretcher offers expansion range from 1‑5/8in to 4‑1/4in. Includes: Steel expander 1 5/8in - 2in Collet, Steel expander 2in - 2 1/2in Collet, 2 3/8in - 2 3/4in Collet, 2 3/4in - 3 1/8in Collet, 3 1/8in - 3 1/2in Collet, 3 1/2in - 3 7/8in Collet, 3 7/8in - 4 1/4in Collet Package List: 1 x Exhaust Pipe Expander Tool Kit (7 Pcs)14 x O Ring1 x Box