Don't let an unexpected downpour turn your carefully packed gear into a soggy mess. The Sea to Summit Ultra-Sil Pack Cover delivers bombproof waterproof protection for your 15L to 30L backpack without the weight penalty that keeps most hikers second-guessing. At just 2 oz, this ultralight pack cover uses seamless construction and durable 30D Ultra-Sil fabric with CORDURA yarns to create a completely watertight barrier that won't fail at the seams when you need it most. The attached stuff sack means you'll never lose it at the bottom of your pack, while the keeper strap system locks it securely in place even when the wind tries to rip it off your external gear. Whether you're day hiking in unpredictable weather or on a multi-day backpacking adventure, this pack cover packs down to practically nothing and weighs less than a granola bar - making it the kind of insurance policy that's so light and compact, you'd be crazy not to carry one.