All you do is slip the capsule on and heat. You can find internet instructions on how to hold the capsule in place with a fork or bent wire while you carefully dip bottle tip and cap into hot water. The capsules shrink closely to the form of the bottle just like the ones on commercial high-end beverages! Fits standard beer bottles and and other bottles the same size or a little smaller. You are bidding on the small capsule marked BEER below at right. The large capsule marked WINE at left is a prop shown to compare the sizes. You will be getting the short capsules. If you need longer capsules, like on the left, see my other items.