World’s thinnest speaker with HTC slim speaker and the HI-END sound quality. This product has an International Patent with the authorization from HTC Corporation. Water repellent and sweat proof cap is suitable for sunny exercises and even in a raining day. Bluetooth built in allows devices to play music and also for your cell phone. Health concern with high quality sound to protect ears from hearing damage caused by directly listening music via in-ear headphones. Long-term wearing without feeling tired is different from normal earphones hurting your ear. Long time standby and continuous play of 8 hours via USB charging is really an ecological and money saving perspective. Allows friends to listen favorite songs together in the same time. Flexible speaker can be designed in any type of cap and easy to clean. No more worries about wired earphones; it must be the best choice as exercising and dancing. Eyeglasses wearing become easy since now we have such a useful Slim Speaker BT Cap!