THIS IS ANGi... ANGi is a patented, helmet-mounted sensor that measures the forces transmitted to your helmet during a crash, as well as the harmful rotational forces that occur during crashes when your helmet doesn’t actually impact the ground.' SAFETY FOR ALL ANGi works with almost any cycling helmet, and there are no annual fees for its service. Of course, all Specialized helmets from 2019 onward are compatible. -ANGi is a ride tracker, crash detector, and safety beacon when paired with the Specialized Ride App. -Includes a one-time activation code. -Detects and reports potentially dangerous helmet impacts to the Specialized Ride app, which notifies your emergency contacts and sends them your most recent GPS coordinates. -Attaches to Specialized ANGi-ready helmets and most other cycling helmets. -Approximate six months' battery life on a 2032 coin cell battery. -Weight: 10 grams w/ battery -Two-year sensor warranty -Two-year sensor warranty