Keep your hand warm when it's cold out. Can be used with retractable or regular leashes, with gloves or without. Water and wind-proof. Great for really cold weather when a heavy glove is impractical with a retractable leash (like if you want to push the buttons), chilly rainy weather, those days when you are trying to shove your hand and the leash in your pocket because it wasn't cold enough for gloves and now your hand is freezing. Leash not included. Also fits a Chuck-It handle so you can keep your hand warm while throwing the ball over and over and over.