REVERB RW-AXSERIES Active X Bluetooth 4.0 Wireless Sport Headphones Featured as Top 5 'Best Buds' in the July 2015 issue of Runner's World: The loudest and most secure fit Designed with the active listener in mind; stays in your ears 100% of the time regardless of how much you sweat or exercise Functions like volume, play/pause/shuffle, power, pairing, call answering and voice command are conveniently located all on one side of the headset for easy access High quality full-figured sound - thick bass, solid mid-tones and crisp highs; sound quality and volume is the best in its class 3 different sized ear buds allows you to find the perfect fit; sturdy design made from hard plastic moves freely never touching the back of your neck