The Zenbivy Dry Sacks feature fully-welded seams for a watertight seal you can trust, instant compression through the high-speed mechanical valve, and durable yet lightweight construction. Our Dry Sacks are compression compatible, not sewn all-in-one. Separate compression will never stress seams, resulting in a more reliably waterproof dry sack. The optional add-on also means you get to choose—leave the dry sack compressed as-is or pair it with our Compression Caps to keep it fully compressed, maximizing precious space in your pack.