The 50cc airbag cartridge Hit Airi s easily identifiable by its red label. It is compatible with airbag vests Hit-Air following: 
Full Airbag Vest (size S)
Full Airbag Vest II (sizes XS and S)
Lightweight Airbag Vest (sizes S and M)
Child Airbag Vest
Child Airbag Vest -25kg
Backpacker Airbag Vest
 
Cartridges Hit Air are announced as a precaution with a lifespan of 5 years, provided that they are not exposed to prolonged heat and that they are kept away from humidity.
The 50cc cartridges weigh 156g gross and contain 38g of Co². As a precaution, it is advised  to weigh the cartridges annually.