The Smith & Wesson hinged universal handcuffs are ideal for both larger and smaller prisoners. The contoured shape of the swinging arm allows these handcuffs to open 25% wider and also close 25% smaller than standard Smith & Wesson handcuffs. Hinged handcuffs are used in applications where subject movement needs further restriction. The model 1 hinged handcuff uses the push pin double locking system. To double lock simply depress the double lock pin on the edge of the cuff with the back of your handcuff key. MEETS NIJ STANDARD 0307.01 Specifications: Wrist Opening: 2.40 First Notch Inside Perimeter: 9.40 Last Notch Inside Perimeter: 5.80 Tightest Inside Width: 1.60 Weight: 12.0 oz Locking Positions: 31 Distance Between Cuffs: 2.00 Maximum Overall Length: 9.85 Two Keys Included