Lead shot - Reduced bulk: Foot sure ankle weights use lead shot, rather than a combination of sand and or iron used in other cheaper brands. This reduces the overall bulk of the weight, thus making them more comfortable during use, and allowing the user to wrap one weight over another or use as wrist weights. Easy to put on and take off: Velcro fastening makes it easy to quickly place them over the ankle, and you can loop the fastener over and hang them up when not in use. Strong materials: The lead shot is sewn into industrial strength nylon bags that go inside the cuff weight as shown. This means that even if the outer layer of vinyl were to tear during use, the ankle weight would still be functional. LENGTH: 18 cm. WIDTH: 13 cm. HEIGHT: 5 cm. WEIGHT: 2.5 kg.