1、Music Helmet: Enjoy rich, full bass and clear mid high tones with our innovative design featuring speakers that are 57% larger, 5dB more sensitive, and a reduced resonant frequency of 180Hz for an immersive audio experience. 2、Enhanced Safety: The smart communications cycling helmet comes with fall detection and SOS functions, triggering emergency alerts through the app for quick assistance in critical situations to improve your safety. 3、Warn Lighting: Built in 270 degree angle LED lights in the helmet can serve as blinking, stop, and warning lights, controlled by the wireless remote on the handlebars, enhancing visibility for safer riding during the day or night. 4、Bluetooth Connection: Easily answer calls and enjoy clear connection with the built in Bluetooth speakers and microphone, to stay alert to traffic sounds, follow GPS navigation, and enjoy music or podcasts while riding. 5、Sports Camera: Built in integrated sports camera allows for convenient and secure recording, offering a simple and easy way to capture your life moments. And is suitable for head size of 54‑59 cm. Item Type: Smart Bluetooth Bike Helmet Material: ABS, EPS, Nylon Helmet Battery: 1400mah Lithium Battery (built in) Remote Control Battery: 300mah Lithium Battery (built in) Application: Suitable for 54-59cm / 21.26-23.23in head circumference 1 x Smart Helmet 1 x Charging Cable 1 x User Manual 1 x Remote Control