Storage by day, pump by night. The Air Stream™ Dry Sack Pump is a dual purpose dry sack and pump. It features a low profile valve plug that is compatible with our multi-function valve found on all of our sleeping mats. With two to three cycles of air, your sleeping mat will be inflated with minimal condensation on the inside of your mat and no dizziness from puffing. The lightweight 15D Ultra-Sil™ Nano™ dry sack is large enough to store clothes or a sleeping bag inside your backpack.