Inflate your sleeping mat with ease - no huffing and puffing required. The Zephyr Pump Sack quickly fills your mat by harnessing air, saving your lungs after a long day on the trail. Attach to your mat valve, open the sack and scoop in air. Give a gentle puff above the opening to help it fill, then roll it down to push air into your mat. Its large-capacity design inflates your mat with minimal effort while preventing moisture build-up, keeping it dry and warm for better sleep.