For those who need more space so they can carry more. Try This Weightless Bag - Impact Reducing Floating Backpack is on a larger frame. and it's water-repellent to protect the devices. 
This Weightless Bag - Impact Reducing Floating Backpack is a 30lb load in your backpack that exerts 30lbs of force (static weight). This changes when you walk or run, where the peak force exerted on you can be up to 3x the weight you are carrying. Suddenly a 30lb pack can put as much force on the body and joints as if it weighed 150 lbs. With the movement of SLT, this additional force over and above the static weight can be reduced by as much as 86%. and this pack is primed and ready for backcountry, hiking adventures, and securely holds enough equipment. your gear and travel essentials will not only be secure, but they will also be easy to access no matter where you may roam.
FEATURES;
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30L capacity holds gear, food, and clothing for a day on the trail
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Permits you to suspend up to 30lbs (more weight can be carried but the pack must be locked)
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The internal sleeve holds a two-liter reservoir for hydration on the move.
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Easy-access secondary pocket stores and organizes digital devices, maps, guidebooks, and trail necessities
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Internal zippered security pocket holds your keys and wallet
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A low-profile zippered external pocket is great for sunscreen, camera, or sunglasses
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External stash pocket keeps emergency clothing layers instantly accessible
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Harness and detachable padded hip belt are constructed of closed-cell foam covered in a 3D breathable "air mesh" to wick water away
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Compression straps secure your gear and minimize pack sway
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Haul loop at the top makes grab-and-go a breeze
