BL Pure Bass Sound: Smartly designed 10mm drivers enhanced by the Dot form factor deliver JBL's Pure Bass Sound so you'll feel every pulsing beat. Product Note: If the size of the earbud tips does not match the size of your ear canals or the headset is not worn properly in your ears, you may not obtain the correct sound qualities or call performance. Choose tips that fit more snugly in your ears. Active Noise Cancelling with Smart Ambient: Active Noise Cancelling lets you tune out sounds while Ambient Aware lets you listen to your surroundings any time. Or turn on TalkThru so you can have a quick chat without having to remove your headphones. 4 mics for perfect voice calls: Enjoy hassle-free, hands-free calls in stereo. The Tune 230NC TWS are equipped with 4 microphones, so you'll always be heard with perfect clarity. Never hesitate to take or make a call again. Up to 40 hours of battery life: Never miss a beat with 40 (10 plus30) hours of battery life or 8 hours, plus 24 hours in the case when noise cancelling is engaged. Need a boost. Speed Charge for just ten minutes to get 2 hours of playtime. Water resistant & sweatproof: Don't be deterred by bad weather. Thanks to IPX4 water resistance and sweatproofing, there isn't a workout or downpour the Tune 230NC TWS can't handle.