Medela Keep Cool Maternity & Nursing Bra DeLuna Elara Chair Flow Settings Standard (1 Battery) as the design features Flow Settings Standard (1 Battery) Dual (2 Batteries) Pulse 1 4 hours 50 minutes 9 hours 40 minutes Pulse 2 4 hours 30 minutes 9 hours Pulse 3 2 hours 30 minutes 5 hours Pulse 4 The H5i's Climate Control system continuously measures and calculates five key variables ambient (room) temperature Keep Cool™ Breathable Maternity & Nursing Bra has two integrated breathing zones to keep you feeling cool and new quick dry technology to help balance your body temperature while offering you support and comfort Our 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