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,
Ridge Hill Shelf on the extent of iron-enrichment, the sandstone may appear predominantly yellow, predominantly purple-brown, or a mottled combination of the two. The shelf is about high on average, and is therefore well-drained. It is largely vegetated by a forest of "Eucalyptus marginata" (Jarrah) and "Corymbia calophylla" (Marri), with an understorey of "Banksia", "Casuarina fraseriana" and "Xylomelum occidentale" (Woody Pear). Some publications identify the Ridge Hill Shelf with the foothills of the scarp, but this is incorrect. The foothills are about 15 kilometres wide, and largely continuous, whereas the Ridge Hill Shelf is no more than 3 kilometres wide and highly discontinuous.