A must-have for the home brewer, each home-brew bottle cap in the love2brew Bottle Caps 50-Pack absorbs oxygen left in the headspace of bottles to protect against oxidation and its staling effects. This makes love2brew caps especially ideal for low-gravity beers as well as brews that will be aged for a year or more. Caps activate when wet for easy application. Fit most standard, pry-off beer bottles. Will not fit twist-off bottles.Manufacturer model #: CAP05. Absorbs oxygen in headspace Prevents premature staling Protects against oxidation Easy application