Material: Acrylic Size: flat size, 23*20cm (hat has elastic band) Lumens: 125 lumens Power supply: battery Light source form: LED Quantity: 1 piece Package Contents: 1pc * LED Knitted Hat 1. Best Music Gift: With the bluetooth hat, you can protect yourself from the cold while enjoying music. It allows the phone to stream incoming calls directly to your audio device without bulky headphones or earbuds irritating your ears. 39;s The connection may be lost. 3. Special LED Design: Built-in and detachable special rechargeable LED lights. There are three lighting modes (high level, medium level, blinking level). It provides a standard USB port for charging the battery. You can charge it with a car charger, computer or power bank. Loading is more convenient. 4. Detachable and Washable: Simply pull up the brim of the LED knit hat and push the light inside to disconnect the light and wash the hat or charge the light, no extra cables required. There is a hole on the edge of the bluetooth device, it is convenient to remove and install the earphone when you want to wash the LED music cap. 5. Wide application: Due to its simple operation and use, the hat is detachable for easy cleaning, especially suitable for those who like to exercise in winter, it can protect you from the cold. Especially suitable for outdoor sports, such as hiking, jogging, running, climbing, skiing, skating, hiking, camping or other outdoor activities.