The Ring Series 2500mAh mobile power bank has a wireless speaker to play your tunes for up to 16 hours. It also has a charging indicator light, carabiner clip and includes a micro USB cable to charge the power bank. Power bank output is rated at 5V/1A. Speaker output is 3w and the power bank charges in about four hours. This product has undergone the most rigorous testing in the industry and is SGS Q Mark certified.