Made From Ripstop Tarpaulin with Sturdy Welded Seam Which is Designed for Years Usage, Tear, Rip & Puncture Proof. Waterproof Guarantee. Solid Roll-top Closure System Provides Secure Watertight Seal. Protect Your Valuables From Water, Snow, Mud & Sand. Just Put Your Gear in Bag, Grab Top Woven Tape & Roll Down Tightly 3 to 5 Times & Then Plug Buckle to Complete Seal.10l & 20l to Meet Your Demands on Different Occasions. Includes an Adjustable & Removable Shoulder Strap for Cross-body or Shoulder Carrying. the Dry Sack Can Floating on Water After Rolled & Buckled, So You Can Track Your Gear Easily. Perfect for Boating, Kayaking, Paddling, Sailing, Canoeing, Surfing or Having Fun on the Beach. "