Medela’s Keep Cool™ Sleep Bra features a full racerback breathing zone for fresher, cooler nights and comfortable, rejuvenating sleep. New quick dry technology helps to balance your body temperature while offering you support and comfort. Medela's 4-way Adaptive Stretch™ technology will see your bra grow with you and extend from pregnancy through nursing – keeping you cool and dry throughout your journey despite your fluctuating body temperature and keeping you supported and comfortable while you sleep.