This speaker comes with a high-capacity lithium battery for extended use before recharging. The design makes it shockproof, dustproof, and waterproof, so it is great for use outdoors. An aluminum alloy carabiner makes it convenient to hang or attach anywhere you want. The effective waterproof level of IPX4 lets you enjoy music and podcasts in the bath or shower. You can also use it as a speaker phone to make or take calls as long as it's connected to your Smartphone. Specifications: Input: DC 5V/1A Built-in 350mAh Polymer battery, rechargeable Speaker power: 1W Product size: 120*53*30mm/4.72"*2.09"*1.18" Net weight: 138g/4.86OZ Working distance: 15-20m Signal-to-noise ratio: >75db Frequency: 200HZ -20KHZ Playing time (at Max Vol): 1 hour Charging time: 1.5 hours Material: ABS + Silicone