What is this tool?

It's a plastic welder (again).

I have one. Welded so many sportbike fairings back together, now I can tell if they are cracked just by holding them in my hands. I've never done any bumper covers.

It's fun to do, but you have to balance because the heat level is rooted in the airflow. changing one changes the other but you might need more heat and more pressure sometimes. I need to put it on a foot pedal electric control.