Koosies

A koozie, also known as a can cooler or bottle jacket, is a sleeve made of fabric or foam designed to thermally insulate a beverage container such as a can or bottle. The primary purpose of a koozie is to keep the beverage cold and to prevent condensation from forming on the outside of the container, which can make it slippery and leave rings on surfaces.

Koozies are often made from neoprene, a synthetic rubber, or fabric with an insulating foam layer. They typically fit snugly around standard beverage cans and bottles. Many koozies are decorated with logos, slogans, or images, making them popular promotional items and souvenirs. The design can vary widely, from simple cylindrical sleeves to more elaborate designs that may include handles or even legs.

The invention of the koozie is generally credited to various individuals in the late 1970s, with early patents filed for similar insulating devices. They gained widespread popularity in the 1980s and have remained a common accessory for outdoor events, parties, and casual gatherings. The term "koozie" itself is a registered trademark in the United States, though the term is often used generically to refer to any such insulating sleeve. Variations exist for different container sizes and shapes, including those for wine bottles and larger growlers.