Lumos Ultra is our most popular bike helmet that comes with integrated LED lighting, turn signals, and smart features to keep you safe in one sleek package. Details:- Length: 10.83" (27.5cm) Width: 8.27" (21cm) Height: 6.10" (15.5cm) Weight 13.05 oz. (370g) LED Configurations Front: 30 White LEDs Rear: 64 Red LEDs COB LEDs for a more uniform look Turn signal capable Automatic brake lights (optional upgrade) Battery Battery Life: 4-10 hours dependent on settings 3.7V 1100mAh Lithium Polymer rechargeable battery 3 hours charging time Wireless Bluetooth 4.0 Certifications US: Complies with U.S. CPSC Safety Standard for Bicycle Helmets for Persons Age 5 and Older EU: CE EN1078 AS2063 F1447 Other Features Apple Watch (Apple Watch App along with its Gesture Recognition features currently in Beta. Read more here.) LS3 Sync Compatibility Team Sync: Read about how Team Sync works here. Lumos Firefly: Read about how Team Sync with Firefly works here. If you have Remote Lite: Flashing Patterns sync, All Power Off If you have Lumos Remote: Flashing Patterns sync, All Power Off, Turn Signals and Automatic Brake Lights Lumos Kickstart Lumos Matrix Lumos Ultra E-Bike