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Rated 5 out of 5 by from No more excuses to stop moving First, for all the reviewers that complained about the fit and being stuck between sizes with no happy ground, there is a 2nd sizing adjustment hidden inside the rear-side pockets. Crank this stealth webbing down and you can shrink the torso way down. I'm 5'-10" 150lbs and the Med is a hair big for running with just the front strap bottomed out but if I cinch up the sides it will fit me when I'm at my racing weight somewhere in the mid to low 140's. The rest is great construction with a zillion pockets accessible while on the move. All these spaces make it a bit heavier than I prefer but the convenience and organization is a big trade off.
Date published: 2017-11-13
Rated 5 out of 5 by from Great Pack, Love the front side oriented pockets I have been waiting for this pack to become available for a couple of months, and the stars aligned for me finally. My REI Rewards, my birthday, and the AK pack becoming available all happened at the same time. As soon as I got the new pack, I took it out on two long adventures, a long trail run and a long hike/climb in the Superstitions Mountains near Phoenix. I have to say that I love the way the pockets are set up to be accessible from the front of the pack. I had everything that I needed without having to perform an advanced yoga pose to access the pockets. I also really like the front side trekking pole attachment points. I am a little worried that the pole attachments may break or wear out, but after the first few uses, I really like the way they work. I really hate having to take my pack off when I am on the trail and this pack made that a non-issue. Very well thought out 3rd generation. I have packs from the first and second generation series, and each version gets better and better. Well done!
Date published: 2016-03-21
Rated 5 out of 5 by from Fits like a glove I have worn this on a few runsto get it dialed in and It took very little time to get all the adjustments just right. It fits like a glove. I'm 5'6" / 135lb and went with the small. I tried both the small and medium as I am on the edge of the chart. The medium bounced around way too much. There is tons of storage for water as well as food/clothing. I can't wait to take it on more adventures!! Thanks UD
Date published: 2016-07-10
Rated 2 out of 5 by from UD has some sizing issues I'm 5-10 and 170 lbs, and per their lower ribcage measurements I'm in the 3 inch crossover point where I could be a medium or I could be a small. I started with the medium and it was too large. The chest straps were fully tightened and it still bounced around too much. I exchanged it for a small, and while it fit a little better, the straps were at the other extreme, but the vest still bounced. I spent half my 14 mile run pulling it down. No amount of adjusting made the pack comfortable enough for me to forget I was wearing it. I feel like a lot of this could have been resolved by making the chest straps elastic. I love the soft flasks. I love the pocket placement...I just can't get the vest to fit me.
Date published: 2016-08-29
Rated 5 out of 5 by from great trail running pack I'm a new trail runner and I'm new to this type of gear. I ordered this pack as well as the Salomon Advanced Skin 12 set because i wanted to compare the two. The Ultimate Direction seems to have a better layout of pockets with more utility and a better way to attach Z poles. The Salomon is a cool pack but some of the straps and features felt like after thoughts and no real utility. At first when I got the UD AK mountain pack it was a little tight under my arms in my lat area. I was concerned this would cause hot spots. I called UD and they said to take it out for a run and it would break-in. I took their advice and now it fits great. When you order this pack make sure and follow the size chart on UD's website and measure the bottom of your ribs.
Date published: 2017-10-26
Rated 5 out of 5 by from This vest is great for my long runs and hikes! I love this vest! I ordered a 2-liter / 70oz reservoir from Ultimate Direction and I couldn't be happier. This vest is light weight, has plenty of pockets in all the right places, includes a backpack, and there is even a spot for my Samsung Galaxy 8 plus on the front. I did a lot of research and planned on buying a different vest, but decided on this one after seeing in REI. I highly recommend it for trail runs, hiking, long walks, or long road runs.
Date published: 2017-08-26
Rated 5 out of 5 by from The bomb Love this pack! I love trail running, and I needed a pack that would work for self supported runs, as well as organized races. It's the perfect size for an all around running pack. The organization is simple enough to remember, yet diverse enough to keep your gear "sensibly sorted". The two features I love most about this pack are: 1. The trekking pole loops on the front. Being able to put up my trekking poles, and access them without removing them makes aid stations and water refills at streams much more pleasant. 2. The sliding sternum straps. Adjust them on the fly for ultimate comfort. This really made the pack easier to get used to. I didn't have to endure multiple test runs, or stopping to adjust in order to get it fitted. Minimal set up time! There are many many other great features on this pack, but I tend to ramble so I'm stopping there. Hope this review helps anyone who is considering the UD AK vest.
Date published: 2017-11-13
Rated 5 out of 5 by from Simply the best This is the most comfortable pack I've ever owned. It has loads of storage for anything you need. Even when it sits directly on my skin there is no rubbing or chafing. The pack feels like a shirt.
Date published: 2016-08-30
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Questions & Answers

How many ounces does each included bottle hold?

Asked by: ABQrunner
​Each bottle holds 17 fluid ounces.
Answered by: REIservice
Date published: 2017-04-01

Can I put a hydration reservoir in the back panel? Does it have a hanger and routing for the tube? If I use a 2L, would there be enough space for a light jacket, snack, and small camera?

Asked by: Meebosh
This vest can accommodate a 2 liter hydration reservoir. The top of the shoulder strap has a strap for hose routing. You should still have room in the main pocket for other smaller items.
Answered by: REIservice
Date published: 2017-06-15

Are the front mount trekking poles holders compatible with telescoping poles or just the black Diamond Z poles?

Asked by: JeramyGNV
Based on feedback and reviews, folding trekking poles are the best way to go.
Answered by: REIservice
Date published: 2017-05-06

What is the chest size for a large (42-44)? Can the pack hold a larger bladder? Thank you

Asked by: Trhone
To get the proper size for the AK Mountain Hydration Vest 3.0, you should measure around the bottom of your ribs with clothes on for the best fit. The sizes are as follows: •SM: 24 - 33 in. / 61 - 84 cm •MD: 31 - 40 in. / 79 - 102 cm •LG: 36 - 46 in. / 91 - 117 cm
Answered by: REIservice
Date published: 2016-08-13

How many bottles does this vest come with? Pic shows one, Details says "bottles" plural. Thanks!

Asked by: Brenden G
The UD AK Vest 3.0 comes with two bottles.
Answered by: Speedy Johnzales
Date published: 2016-06-06
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