I had an oil pan plug that was rounded off very badly. On the end of ratchet this tool wouldn't grab. However, on the end of an impact driver it dug in and held firm. I believe that if there had been some form of the original hex head left on the plug then the tool would have worked fine on the ratchet. Before buying this set I sought it from another high quality tool maker. The Craftsman set was the best value. I'm very satisfied!
These tools have saved me countless hours of undue aggravation. They've loosened rusty manifold studs, air conditioner compressor head bolts, oil drain plugs, and even stubborn intake bolts.
I'd reccommend them to anyone that has a shop or just does work on their own cars. What an invention! I remember the first Bob Vila commercial that advertised these things. And everytime I see the Craftsman logo, I know it must be a quality tool.