Great set of concrete pieces but with a fun and useless storage bag. Advantages: 1. They use the SDS clamping system developed by Bosch for hammer drills, are firmly fixed, will not slip or loosen in shock mode.2. They are also made, if not better than, similar bits from Bosch and Hilti, but at a fraction of the price3. They have been pre-oiled/coated to prevent rust4. The tips were sharp and chewed off when throwing bricks, as if for business. Cons: 1. My only criticism of these bits is theβ¦