The Mammut Refillable Airbag System Cartridge is the critical element for your Mammut RAS (Removable Airbag System), Protection Airbag System, and older Snowpulse avalanche airbags to work. Once you've filled this empty cartridge to 3000PSI and installed it into your airbag system, it's ready to deploy the buoyant airbag that helps you remain on the surface of an avalanche. For durability, a valve protector has been added, and filling pressure can be controlled via an integrated pressure gauge. The cartridge must be filled after each use at an authorized refill center.