1. Heavy-duty drop forged, hardened, and tempered chrome vanadium steel construction for unbelievable durability. 2. 72-teeth need as little as 5 degree to move fastener while a regular wrench needs 30 degree of sweep space. 3. Finely polished chrome plated and mirror finish will protect against dirt and corrosion for years to come. 4. Small head profile for easy access to the tightest of spaces. Best application for confined space and car engines. 5. Packing: in elegant plastic rack convenient for hanging and storage. Then inner white or color box then outer packing. 6. Plastic rack with convenient handle for easy accessability and storage. The front lock keeps the wrench in place steadily. 7. All wrenches are clearly marked with the size in four places on two sides for easy identification.