Product Description Alpinestars Tech-Air 5 System Electronics System: Active electronic system that features six triaxial integrated sensors (3 gyroscopes and 3 accelerometers) Crash algorithm that leverages AI to accurately monitor when to deploy the airbag in the event of a crash 30 hours of riding time after a full charge via micro USB charger Bluetooth and App integration Capable of both Race and Street use Airbag System: Covers shoulders, chest, ribs and full back Maximum inflation time of 20-40ms based on the volume of the airbag size Decreases impact force by 93% compared to a passive protector Includes argon gas canisters Highly ventilated back protector Leave elbow and shoulder armor in your jacket, but removing the jackets back protector is recommended (since the Tech Air 5 has one built in) Operation: Zip up vest and close magnetic flap Integrated LED display indicates operational status To activate: VELCRO® brand closure at the top of the zipper contains a sensor that arms automatically when closed. Sizing Note: Tech Air 5 should only be worn UNDERNEATH a properly fitting Alpinestars Tech Air ready jacket or any jacket with 1.57" (4cm) of space around the circumference of the rider's chest.