There's no carnival while hiking down the trail or paddling across a serene lake, so why bring a balloon along for the ride' Now you don't have to when you're carrying the SealLine Blocker PurgeAir Dry Sack. This dry sack features a PurgeAir valve that releases built-up air from ballooning it out inside your pack or kayak storage area. Waterproof materials ensure your gear stays dry, even if the sack falls into a puddle or gets a hefty splash in your kayak. It uses a secure roll-top design to keep unwanted water out and reduce its overall carrying bulk. Welded seams increase durability and don't allow water inside the sack, so you'll know it's worthy of overland and nautical adventures alike. Additionally, you'll find it's designed with flat-shaped sides that reduce its carrying bulk over rounded dry sacks.