JBL Pure Bass SoundThe cleverly designed 12mm drivers, enhanced by the physical design, deliver JBL's Pure Bass sound so you can feel every pulsating beat.Active Noise Cancellation with Smart AmbientHear more of what you want and less of what you don't. Active noise cancellation technology with 2 microphones lets you minimize distracting sounds.With Ambient Aware, you can tune into your surroundings at any time, so you feel more confident when you're out in the world. With TalkThru, you can have a quick chat without having to take off your headphones.4 microphones for perfect callsExperience seamless, hands-free calls in stereo. Tune Flex is equipped with 4 microphones, so you'll always be heard with absolute clarity. You'll never have to hesitate to answer or make a call again.And with VoiceAware, you can choose how much of your own voice you want to hear by controlling how much sound is sent from the microphone to your earphones.