Marmot Graviton 48 Backpack
You can grab items from the top, bottom, and middle of this pack without having to fish around.
Brand: Marmot Gear Reviews
Model: Graviton 48 Backpack

Access
This top-loader also has a 35-inch, J-shaped front zipper, which provides all the benefits of a U-shaped zipper but saves weight. Multiple zipper heads meant we could access the gear we needed without undoing the whole thing. However: The side compression straps run across the zippers, which is a hassle.
Suspension
A modified trampoline-style backpanel provides a half inch of ventilation between you and the pack, but the frame isn’t as bowed as many we’ve tried, enhancing interior space. “It doesn’t compromise the volume of the packbag, yet I could feel the flow of air cooling my back as I walked,” said one tester after hiking down to the Pacuare River in Costa Rica.
Durability
The priority here is on weight savings: 100-denier ripstop nylon (lighter than most) covers the bottom of the pack, while lighter, 70-denier ripstop nylon makes up the body. One tester reported moderate abrasion on the bottom of the pack after a month of hauling heavy climbing gear.
Bonus
A large, 9-liter detachable lid keeps gear handy; remove it to save 5.1 ounces.
