Force gloves create a webbed hand for exercises and swimming. They increase resistance by 50 percent. The neoprene palm and backing allows for gripping of gear and zipper closures with zipper locks secures the force gloves fit. Color coded sizes. Glove Sizing (measurements in inches - back of hand X wrist to tip of middle finger): S: 3.25 X 6.5 M: 3.5 X 7.25 L: 3.75 X 7.5 XL: 4 X 8