Have the Allen wrench set purchased in January and use it several times a week since for various purposes. The keys have a good quality, the heads are still perfect. It makes more than the screw head broken. Even if the key with tubes or similar extended bend the key only during the application of force, then he goes back to its original shape. Only the smaller keys cut at greater Kraftanstregung the flesh.
If the key at any time to buy again and recommend!
