Zippers are cheap and fits snug especially over chest protector. Very little adjustment to make largerI think this is a good product but a bit too snug on my chest. I have a muscular build and have a slightly above average chest-size for a guy, and found it disappointing that the adjustable straps had limited variation.Perfect bag for trail riding! Strap system is the best!I have been using Camel Backs for years but after my first long MTB ride with USWE I am never going back. Straps are awesome, the pack feels tighter to the body, storage is optimized, and is just feel good.Love it. Filled with water, keys and small tool kit. Not idea it was strapped to me.Really comfortable. I like the small size of the backpack. My one complaint would be the hose doesn't detach, which makes it difficult in removing the hydration bag from the actual backpack. Seem durable enough. Time will tell.Awesome hydration pack....a little snug on my body with my chest protector on.I got this pack for mountain biking and I must say I love it way more than my camelback. It doesn’t move at all