Womens open cup bra is a style of bra where the cups are either partially or fully open, leaving the bust exposed. The open cups may be half quarter or having just underbust and side support. The underwires and adjustable bands are why this bra can lift and support the breast. Open cup bras are known for their bold and unique design that is sexy to the core and perfect for a romantic look. They come in a variety of styles, from those with minimal coverage to styles with intricate details and luxurious fabrics.