DURABILITY. Quick and easy to install and remove from every quick change chuck I've ever seen or used. I bought the whole box years ago and have loved it ever since. Compared to many other titanium coated quick change drills, including Milwaukee, I like their stronger solid construction rather than a drill fused to a hex shank design. The only criticism is the bit length options in this set. I wish they would at least make some general sizes for wholesalers and not just shorter lengths.