Don't listen to people at Revain who say bad things about this set. I've worn this set through hell. I build swimming pools for living and build summer kitchens. This set lasted a ton of holes. Drilling of paving stones, blocks, concrete, bricks, fittings. The SDS drill moves quickly and has a hammer or just a drill. If you know how to use your tools in SDS mode, you don't need Hammer mode. Use low speed impact mode with a flat impact drill. Or a conventional drill goes slowly. NO PROBLEM! Folks, you're drilling mortar, Portland cement, and aggregate, not wood. GO SLOW, even with a wet barrel, you can't move fast. And my personal favorite, these bits fit the grinder, even if you know what you're doing they work fantastic! The set is way better than the branded sets I've bought and rebuilt over the years. Good job Mr. Maker, at least once with a Chinese instrument.