A "crowler" is a type of container used for packaging draft beer. It is a large, resealable aluminum can that typically holds 32 ounces of beer. Crowlers are popular among craft breweries because they allow customers to take fresh beer home without the need for traditional glass growlers. The process of filling a crowler involves using a special machine that fills and seals the can on-site. This helps maintain the beer's freshness and carbonation. Crowlers are often used for limited releases or seasonal brews, making them a convenient option for beer enthusiasts looking to enjoy their favorite craft beer at home.