They're designed to be able to remove stripped torx heads. There is also a set that does stripped hex heads. Stanley black and Decker owns the tool brands Mac and Proto, as well as the patent on these two types of sockets. As a result, they sell the hex set for about $115 through Mac and about $70 through proto, however the torx set is $200 and is exclusive to Mac and of course it's the one I need. No other company stateside has a product even remotely similar and I'd rather give the local owner operator the business than ordering through Mac corporate. My current application is a T40 with stripped cams on a pressure plate fastened to my engine. There isn't any clearance next to the bolt head to use the standard $18 bolt extractors, and I'm not chancing an e-z out to make it worse. I've been in this position before, I'm sure this won't be the last is how I've justified it. Frankly, if they work as intended, this set will pay for itself at its first use.