ZoN Thumb Lock Wrist Weights: * Specially designed thumb hole keeps the weight from slipping around the wrist * Sold as a pair of 1-lb (0.45 kg) weights (Two 1-lb weights per package) * Contoured body and soft sand filling conforms to the hand and wrist * Adjustable hook and loop on ends for a secure fit * Soft, comfortable neoprene cover is also slip resistant