The 30L R.A.S. (Removable Airbag System) has all the features of the standard 30L pack plus the pockets that hold the Snowpulse R.A.S. removable airbag system. The R.A.S. system allows you to use the pack with or without the airbag installed and utilizes compressed air instead of nitrogen so you can deploy the bag before a plane trip and then easily refill the canister at your destination. With the R.A.S. system onboard, it weighs 6lbs 7oz and the R.A.S system takes up only 4 liters of space within the pack.