Manufacturer Part Number (MPN) : 4703N850CN Hinged Cuff - Navy. The hinged design provides additional restraint by more effectively restricting hand and arm movement. All hinged models features an improved internal lock mechanism for increased tamper resistance, smoother ratcheting action and greater durability. These models incorporate spun rivet construction, push pin double lock capability and fold flat for compact storage. Two keys supplied. It has a 10% larger inside perimeter then the Model 700C and Model 750C. The Model 850C are National Institute of Justice 0307.01 certified and come with a lifetime warranty for manufacture defects.