I bought two of these to prep my chassis prior to painting with FCP and CIO. I found them really easy to control meaning I could be careful with what material I removed. I've never used a flap disc as good as these, they just keep working until they are down to the backing disc, I only used one on the chassis in the end so I used the other on my bumper which I took down to bare metal and it's still got loads of life left.

This flap discus superb and cuts through layers of old paint as well as removing nasty rust spots also cuts through the rough welds if you have any

I recieved a pack of these a few weeks ago. Came within 3 days and i've been using them for a good, solid 6-8hours of more....and im still on my first disc.. they sharpen them selves right down to the backing pack without any of the "smoothing" effect. Just ensure you know the precautions when using a 5" disc rather than a 4.5" (unless you have a 5" grinder. Overall.... i wont be buying anything else on the market except these.