Tailpipe Expander?

I grabed one from Lesile at a local store. It has a 3/4 hex head you twist to expand. The tool is fine for getting two exact size pipes to fit over each other. Sometimes, like when you buy a pipe to fit a gap with a new muffler, the connector pipe is the same exact size, this tool is worth it. Though, mine, again, has a 3/4 hex head. It requires a good muscle day or air gun with a high torque rating.