Super lightweight, cool and comfortable, the Hit-Air Airbag Vest* Model SV2 is designed for rider sizes 2XS-S. Neck and torso, hips and spine are cushioned with air if the rider falls off the horse. A high-speed airbag deployment system uses a CO2 cartridge to inflate the vest in .25 of a second; the inflated vest helps absorb impact. After the airbag inflates, air is slowly released through a release valve. It’s so cool and comfortable, you’ll hardly notice it while riding. Includes one CO2 cartridge and coiled wire lanyard.