About this item NOTE: If headset is too tight we suggest placing them over a ball or something of similar size/shape. Leave undisturbed for at least 24 hours. Repeat if necessary. Please also try length adjustments of either earpiece until both sides best fit you. JBL PURE BASS SOUND: These wirelss headpones feature the renowned JBL Pure Bass sound, which can be found in the most famous venues all around the world. WIRELESS BLUETOOTH: These headphones stream wirelessly from your device and can even switch between two devices so that you don't miss a call. UP TO 40 HOURS BATTERY WITH SPEED CHARGE: For long-lasting fun, listen wirelessly for up to 40 hours and recharge the battery in as little as 2 hours with the convenient Type-C USB cable. A quick 5-minute recharge gives you 2 additional hours of music. MICROPHONE ON EAR CUP FOR HANDS-FREE CALLS: Easily control your sound and manage your calls from your headphones with the convenient buttons on the ear-cup. ASK SIRI OR HEY GOOGLE: Siri or Hey Google is just a button away: activate the voice assistant of your device by pushing the multi-function button. Featuring an adjustable headband the Tune 510BT are designed to fit nearly any head size comfortably › See more product details