Question about Hövding 3 Airbag

How should the following statement be understood? "The airbag is easily charged via a USB cable and then offers you safety for 15 hours of active cycling pleasure at speeds of up to 20 km/h." what happens if you ride faster than 20 km/h? long downhill rides, even urban ones, can quickly reach 50 km/h. is the product suitable for this?