63/57/51MM Exhaust (Step) Adjuster Pipe. These little friends help you to fit a muffler on a modern exhaust. Available in multiple sizes and in stainless.

This one:  63/57/51MM
This is the outer diameter
The material has a thickness of 1.5MM

So, a 63/57/51MM pipe has a 60/54/48MM inner diameter.

Price PER 1 piece