The AirStream is our big-volume sleeping mattress pump, it is based on our 20L Ultra-Sil Nano Dry Sack, with added valve plug and foot loop. Using the venturi effect means the 20 litre Air Stream can be inflated with a single breath. Two to three cycles from the Air Stream are enough to fill Sea to Summit Sleeping mats, meaning youre ready to go quickly, with minimal breath condensation in your mat, or dizziness from blowing the mat up. The Air Stream can be used as a 20L dry sack or ultralight pack liner.