Description Tougher case. Tougher blade coating. Tougher hook connection. Our Extended Performance (XP) Tape Measure is our toughest ever. It is built around our Dual-Core⢠Technologyâa patented spring system that uses two retracting springs in an impact-resistant, heavy-duty case.Integrated lock protection guards the lock button when dropped.Our toughest blade coating protects the paint and prevents rust longerThe built-in lanyard slot offers an additional security option.