The Vevor exhaust pipe expander tool kit is designed to precisely expand exhaust pipes from 1-5/8" to 4-1/4" for secure, smooth-flow connections. Built from hardened carbon steel and aluminum, it is suitable for low-carbon steel and stainless steel pipes with wall thicknesses up to 0.06". The kit includes 7 collets to cover a wide range of pipe sizes for repair shops and home garages. A rugged storage case keeps the components organized and protected for transport and storage.