Amazon.com: Hit-Air Moto ST Airbag + Built-In Protection,Amazon.com: Hit-Air Moto MLV2 Airbag Safety Vest with CO2,ST-C | Airbag is stored in the neck and lower back by Velcro,81gs1nJOVLL._AC_UY1000_.jpg,Structure and kind of airbag | hit-air airbag system