Sentry Industries 2ACP4BT350 allows you to enjoy your favorite music or podcasts wirelessly, thanks to the Bluetooth connectivity. It offers up to 2.5 hours of talk time on a single charge and has a standby time of 180 hours. The in-line controls let you pause the music, adjust the volume, or skip tracks without taking your phone out of your pocket. You can also use the built-in microphone to answer calls without removing the earphones. With a frequency range of 20Hz-20KHz and a driver unit of 7mm, these earphones deliver clear and well-balanced sound.