A. Wireless Bluetooth technology: This wireless music cap can pair with any Bluetooth-enabled smartphone or tablet relatively fast and easily. The wireless transmission distance can reach up to about 33 feet, providing around 5 hours of music playback or talk time. It is suitable for outdoor sports. B. Two-in-one Bluetooth earphone and sports speaker: This Bluetooth speaker cap enables you to listen to music without wearing additional earphones. It is also equipped with a microphone so that you are less likely to miss any incoming calls. It is suitable for outdoor activities such as working out in the gym, fishing, running, skateboarding, hiking, camping, and skiing. C. Stylish, comfortable, and washable: This Bluetooth wireless cap has a simple panel display on the ears and is equipped with 3 prompt buttons for basic operations like pausing/playing music, answering calls, skipping songs, and controlling the volume. The Bluetooth baseball cap is relatively easy to disassemble and reinstall, making it convenient for you to wash the cap. You can hand - wash it after removing the Bluetooth module. D. Good audio: This Bluetooth speaker cap has good stereo sound output and can pair with smartphones or tablet devices relatively quickly and easily, allowing you to enjoy music at various times and places.