Dry Seal Roll-Top Closure Made with continuous double sealing strips, our roll-top closure is more waterproof than any other. Instructions are embossed directly on the strips, making it easy to get a reliable seal. Simply fold the top of the bag downward between the strips, squish out any trapped air, fold a couple more times, then buckle. Heavy-Duty 30-oz. Vinyl Bathtub Bottom Improved Suspension System Our best-selling portage pack is now even better, with an improved suspension system that includes breathable/waterproof shoulder straps, as well as a waist belt on every size. This pack is great for everything from canoeing and canyoneering to protecting your gear on trains, buses, boats, and float planes. It features our watertight Dry Seal roll-top closure, along with a heavy-duty, 30-ounce scrim-reinforced vinyl bottom and 19-ounce scrim-reinforced vinyl body. Available in three sizes: The 115 L and 70 L sizes close with side-cinch buckles, while the daypack-size 35 L includes a top buckle closure. Boundary Pack 35 Weight: 1 lb. 14 oz./850 g Volume: 2270 cu. in./37 liters Size: 10 x 14.5 x 20 in./25 x 37 x 51 cm Color: Blue, Black, Green, Yellow