Review on Mixiflor 24Pack Abrasive Flap Wheel Sander: Efficient Cone Shape Sandpaper for Rust Removal, Weld Burr Removal, and Grinding by John Hashman

This set will last just because there are so many of them. My employed mechanic always uses flap discs first and not the traditional corundum grinding disc. He says they are unbeatable when it comes to welding preparation. He even has a flat disc (not offered here) on his angle grinder instead of the usual serrated disc. Although I've never seen a cone sander, I'm sure they have a use, especially in woodworking. Judging by their appearance (shipped in a flimsy crumpled up box inside an envelope) they're not top quality, but I don't think you can go wrong at the price point. The largest grinding wheel is rated at 8000 RPM, so keep it away from air tools like grinders. In a cordless drill, however, they are ideally portable and versatile.