Note: this item was provided for review.
If I were asked to put my thumb on the pulse of small men’s bags, I would say we are on the tail end of slings being overtly popular/acceptable. That’s to say, it’s not something you’ll see everyone carrying, but certainly not something which will draw attention if you carry one. I’ve long been a fan of a good sling, though with my own ups and downs on how often I use them. Pioneer Carry was kind enough to send over their new A4U Sling, which was produced as an item they wanted (aka limited run) to see how it fairs in the wide market of slings.
True to the brand, it’s well made, and smartly designed, and dare I say — one of the better pure slings I’ve tested.

Materials and Capacity
The sling you see here is the ‘Blue Crush Baby Ballistic’ color, though in person it reads far more navy than blue. The outer shell is 840 Baby Ballistic, and it is lined with 10XD in classic Pioneer Carry fashion. Baby Ballistic is ballistic nylon adjacent: less shine, smaller weave pattern, but with the same level of “slippery” that ballistic is known for. It feels very robust, and has a nice appearance overall. The strap is an impressively stiff nylon webbing with a nice visual border pattern, no padding, and only a metal slider to adjust the length.

The sling only weighs 8oz empty, but it is quite small at 11.5” x 8” x 2.5” — with a stated capacity of 2.5L. Though, I would gut check that closer to 2L than 2.5L as a practical capacity. It is designed to fit A4 sized items, hence part of the name and shape.

So, you’ll ask me next, does it fit an iPad? It fits an iPad Mini, smaller Air, and iPad Pro 11” (M4) in my quick checks. Though without a case on the 11” Pro, and it’s not the most roomy fit.

In Use
When this arrived I had a “hrmmm” moment, as it was smaller than I imagined in my head, and bordering on “is this even big enough to be useful” in my guessing. What I didn’t expect is the overall utility of such a small bag, and how often I find myself constantly grabbing it as the solution when I head out.
But, it’s not the size of this bag which drives the utility. Instead it’s the functional design, and lack of fuss the bag demands. What I mean by this is exemplified by the strap itself: you can adjust the length and do nothing else. It’s articulated so that the bag sits nicely when worn across your body, but still allows for easy one-shoulder carry if that’s your thing.

There’s no disconnect points, the adjuster has no quick adjustment, it’s more intentional in the design. Don’t fuss about with adjusting the bag, just get on with life.
There are three main areas of this bag:
- Two front pockets, which each have their own volume. One of the pockets has a strap you can snap your keys on to, the other does not. These pockets are dimensional in stitching, so they can be pressed flat, but also have a good amount of volume in each. They can hold my iPhone 16 Pro, but only with two hands working the phone into the pocket, and pulling the top flap over it. They are much better suited for things like a wallet, snacks, tissues — and other quick to grab items.
- The Main compartment opens with a simple flat and straight zipper across the top. Inside is an open space with a single hanging pouch, which provides an open top pocket, and a zippered compartment. This hanging pouch is lightly padded, it’s here in that the open top hanging pocket you’ll find the best spot to store your phone. While this compartment can squeeze an 11” iPad Pro, it won’t do so with much else in the pocket or on the device. It also will not hold my Leica Q2 and still zip closed (though I suspect it might hold an X100 series camera).

At first I kept thinking: there’s just no reason for this. All of my gear I would normally carry in my shoulder bag was far too much for this sling. It took me a bit to realize what this really is good for: the little things you don’t have room in your pockets for, but which can make your life infinitely easier when and if you need them if you actually have them with you.

Here’s what I have been carrying in mine:
- Peak Design Packable Tote Bag: something I need almost always when I got out, but unless I am carrying another bag, I rarely have it on me. The A4U makes it very easy to carry with me.
- Observer Collection Papa Notebook w/ Tactile Turn Side Click pen.
- Pack of Kleenex.
- Protein bar.
- Grid linen wash cloth.

I tend to toss my wallet and keys in the sling once I am out and about as well. The only downside to this is remembering to grab it when I get up to leave a coffee shop, as it’s small enough that sometimes I don’t notice if it is still on me or not. In fact, because of the size, it’s fairly easy to put this inside another bag for storage when needed.
I only have a couple of nitpicks on this, but I am not even sure if these should be changed, or if it would make this better or worse if they were changed:
- The strap is quite stiff, and I do think a softer strap would make this sling easier to store inside another bag, or even just to manage getting the strap out of the way when you are not wearing the bag. That said, the strap as it is, is very nice to wear overall and I would not want to lose that. It offers a good amount of grip on top of slippery fabrics to keep it from sliding off your shoulder — a nice plus. The only time you notice the strap is this stiff, is when you are carrying/holding the bag by the strap, on your body, it’s no issue.
- The two front pockets both have the zipper running in the same direction. Which means that when they are closed one zipper pull is at the center of the bag, and the other at the edge. What I would expect is the opposite of this, that both zipper pulls sit on the edges, or the center, when closed and thus run away from each other. This tends to trip me up a bit when I go to grab for the zipper pulls.
- I would prefer a slight change to the main compartment zipper pull, as it leaves a small 1/2” gap when closed, and something which fully closes would offer a lot more secure storage of smaller items — nothing has fallen out, but that’s more because I have put nothing small in this area after noticing this than anything else.
Three things that’s it, but as it is right now, I’ve been impressed and I will certainly keep using this. Pioneer Carry notes a heavy focus on using it when traveling, and I can certainly see this bag becoming a go to for that use with me.

Around town there’s been no odd looks, nor have there been in more remote areas of Colorado I have traveled with this — in part because so many people here are constantly carrying bags, whether slings, fanny packs, shoulder bags, or backpacks. Colorado is a very bag friendly state, and so it’s hard for me to gauge what general perception would be. My guess is that on the West Coast, and Northeast, you’d be fine. But if I were back in Texas, I’d be getting cringe-inducing ‘purse’ comments — as if the purse is somehow not one of the most practical items we buy.
I was worried that at 6’-3” this would look comically small on me carrying it. And it certainly does look small. But I think it is the ‘small of it all’ which takes this from being an awkward carry, to a natural and easy carry bag.
Overall
This is a really nicely made sling, with excellent materials, and a unique size and shape on the market. It’s laid out exceptionally well for non-work style carry, and has just enough to make your life easier without constantly being in the way.
Then there’s the price, at $134 this is an excellent value for what you get. Very much recommended.
