Bra allows the wearer to use the tighter hooks as the bra stretches during its lifetime. Bras may be designed to enhance a woman's breast size, or to create cleavage, or for other aesthetic, fashion or more practical considerations. Nursing bras are designed to aid breast-feeding. Compression bras, such as sports bras, push against and minimize breast movement, whereas encapsulation bras have cups for support. Breast support may be built into some swimsuits, camisoles and dresses. Bras come in a variety of styles, including backless, balconette, convertible, shelf, full cup, demi-cup, minimizing, padded, plunge, posture, push-up, racerback, sheer, strapless, T-shirt, underwire,
Shelf life after their shelf life, and, as a cost-saving measure, the US military routinely uses a wide range of SLEP tested products past their official shelf life if drugs have been stored properly. Preservatives and antioxidants may be incorporated into some food and drug products to extend their shelf life. Some companies use induction sealing and vacuum/oxygen-barrier pouches to assist in the extension of the shelf life of their products where oxygen causes the loss. The DoD Shelf-Life Program defines shelf-life as The total period of time beginning with the date of manufacture, date of cure (for elastomeric and rubber products