http://www.rcnitronation.com/product...45165eb41ef29b
One of the best investments I have made. Going beyond 6 kit builds & all the maint along the way & just now dulling but I have abused them no end. I also have the ball set & standard & ball SAE sets. I tend to use the straights as ball wrenches when I have to.When I got them they were hard & sharp enough to cut glass & would take out stripped head screws if you cock them over. Life time guarentee they have but not needed. I have only broken the smallest SAE one by dropping the car with the wrench still in. The extending feature is also the greatest thing since sliced bread,the tip stickes out less than a inch when in & seems to be the perfect length when out or anywhere between,also have a hole in end to use another wrench as a T-handle. My 2mm & 2.5mm are the ones worn & I'm fixin to purchas another set instead of warranty pecause I appreciate this product that much.