An ABS avalanche airbag is an awesome thing to have, but can only be deployed once without needing replacement parts; keep your ABS airbag pack ready to use and always have a spare Activation Unit on hand. This package consists of a canister of compressed nitrogen—which is used to inflate the bags because it resists icing at low temperatures—and a trigger that activates the canister. Once you've used your existing canister and trigger, both must be replaced or refilled, which must be done by a certified ABS refiller.