The Compression Sack is the perfect solution for squishing down bulky soft items for organized packing. These burly sacks are built from a water-resistant 70D Nylon fabric, offering excellent strength to weight. They can allow compression down to one-third of their original volume, which means you save valuable space in your pack for other essentials. HIGHLIGHTS Packability: In a perfect world, with perfect contents this compresses down to 1/3rd of its original volume (i.e. from 15 to 5 liters) Best Use: Internal pack organization, packing up whatever you feel like belongs in a bag that can be compressed FEATURES Flip-Top-Lid design prevents strap tangling Made of 70D PU-coated Nylon 4 straps for even compression; eliminates bulging Extra long straps so it&';s easy to fill these to max capacity Nylon webbing pull handle on the bottom Note: Seams are not tape-sealed; therefore this product is not waterproof - only water resistant What this bag could hold 30 liter: Sea to Summit sleeping bag and your extra layers