Storage by day, pump by night. The Air Stream Pump Dry Sack features a low profile valve that connects to the multi-function valve on all of our sleeping pads. With two to three cycles of air, your sleeping pad will be inflated with minimal condensation on the inside of your pad, leaving you with no dizziness from puffing. The lightweight 15D Ultra-Sil dry sack is large enough to store clothes, or a sleeping bag inside your backpack. Best Use:Storage by day, pump at night Weight:1.7oz | 48g Volume:20 liters Compatibility:All Sea to Summit sleeping pads FEATURES Inflates most Sea to Summit sleeping pads in only two to three compressions. Fully seam-sealed dry sack with valve plug. This 20 liter volume product is perfect for storing clothes or a sleeping bag inside your pack. Packs down extremely small.