Edge Leather Hand Grip Wrist Cuffs from Sportsheets. Nickel free metal is hypoallergenic and body safe. Edge bondage products for keeping couples connected. Includes 2 wrist cuffs. 100 percent nickel free metal. Color Black. Materials Leather, Metal. Measurements: inside adjusts from 7.5 inches to 12 inches, inside diameter range when buckled is 2.86 inches to 4.62 inches.