Place your phone or device on the top of speaker and the sound will instantly amplify.</br>Compatible with most smart phones and MP3 players with external speakers.</br>Built-in rechargeable battery: charge via micro USB cable (included).</br>10 hours play time for per recharge.</br>The speaker is perfect for outdoor entertaining or travel.</br></br>Product Description</br></br><b> Description: </b></br></p> ? Equipment with no speakers feature use optional 3.5 mm jack cable?? please connect this speaker.? </br> ? This speaker with volume control features. In the Smartphone side please adjust the volume. </br> ? Depends on direction and location