I bought this because I had used a PDR glue tab on a dent in my car and overpulled it and needed this tool and tap to tap down the over pull. I selected the tip to use and was able to level out the ding so you can't tell that there was ever a dent.
I've only used it twice but it saved a ton of time. It is perfect for repairing style lines.
I have not used all the heads yet, but so far the ones I have used are working out well. The material of the heads seams to be a high quality hard plastic, or just straight up aluminum. Whatever it is, it seams to be hard enough to push dents back in, but gentle enough not to scratch or chip paint
I love this thing very solid construction, well put together , The handle is very well-made very even strike 2 cars so far and it's holding up nicely .
It's a good tool to have once I get better at the technique of tapping. It is a learning skill that can be perfected by a determined individual.