Don’t be fooled by those cheaper finger style pipe expanders. Those are simply to remove the crimp a u bolt style clamp leaves in the pipe and they typically break doing that! Don’t dare stick an impact on those things!
This tool actually expands the pipe enough to be able to be to slip it over the next to make Welding and fitment easier. And you NEED a good 1/2” impact to work it but it will Leave you with professional results every time.
This one only comes with two sizes so if you need anything larger then what provided you will need the other sizes or buy the bigger kit.