UPDATE: Make sure you use the waterproof tarp lining that comes with it. For me it has been over 6 months, and the black inner lining of the bag is getting pretty worn out, especially at the bottom of the bag. I have not been using the waterproof tarp liner that came with it, because I thought that not using it would make it easier to open. I believe that using the liner will prevent this wear from happening, and I wish I had done that from the beginning. Just keep that in mind when you're using this.----------I've had this backpack for a couple of months now, and I used it every day when I was working for Jimmy John's as a delivery courier in Seattle, Washington (rainy!). This backpack is amazing. I'll try to go over all of the features.Main compartment: MASSIVE. And when it's not all the way full, the bag can be easily cinched down to be more flush with your body. There are no other pockets inside the main compartment, its just a simple, big container. Completely water resistant with drainage grommets at the bottom. It also comes with a removable plastic liner if you want the bag to be totally water proof. Without the liner, the bag was able to fully protect paper sandwich bags in surprise Seattle cloudbursts.Outside pockets: One velcro pouch; I use it to carry my keys, bike lights, bike computer, etc. 2 pen pouches, and one slightly bigger pen pouch. One big zipper pouch that you can use to carry things that you need easy access to, like a wallet or sunglasses. All of these pouches are hidden underneath the flap so they will also stay dry instability.Side pockets: Huge. Big enough to fit a 1 liter nalgene water bottle with space leftover. They don't secure shut, but in all the riding I've done nothing has ever fallen out of them, even when I've fallen off my bike. They're also big enough to securely hold any U-lock.Straps: The shoulder straps are adjustable, and they come with a removable cell phone pouch which is big enough to hold any smartphone. It also has a chest strap and waist strap for extra stability.Outside flap: Simple buckle shut design, you can reach behind and undo it with one hand while its still on your back. The 2 stripes on the back are super reflective and look badass.If you're a bike commuter or a courier, I highly recommend this bag.