🔥 Get up to 15% off ALPAKA • Join Pack Hacker Pro

ALPAKA Modular Sling Review

The ALPAKA Modular Sling doubles as an add-on pouch for your bag, though when used as a sling, the interior layout doesn’t make the best use of all its volume.

Our Verdict

7.1 /10
Good info






Unlock the Pro Summary

Save time. Get access to brief summaries of our reviews so you can browse and make decisions more efficiently.

Join Pack Hacker Pro or, Sign In


  • Made of durable and waterproof X-Pac fabric
  • Can add storage to other bags
  • Wears at a natural angle that sits comfortably


  • Too big to mount on a backpack’s shoulder strap
  • Magnetic flap can have a hard time sticking when front pocket fully packed out
  • Vertical shape leads to wasted space

Technical Details

100 %

Carry-on Compliance

View 145/145 Airlines

30 %

Like the Look

Polled on Instagram

  • Dimensions

    7.48 in x 4.17 in x 1.97 in (19 x 10.6 x 5 cm)

  • Notable Materials

    YKK Zippers, X-Pac, Ripstop Nylon

  • Manufacturing Country


  • Warranty Information

    Warranty & Repairs

Full Review

Get up to 15% off ALPAKA • Join Pack Hacker Pro

Slings are already versatile in their own right. They’re small, easy to carry, and have just enough space for all your everyday carry gear. So what happens when you add the word “modular?” Does it become even more versatile? Well, the short answer for ALPAKA’s Modular Sling is yes. However, the long answer is a bit more complicated.

ALPAKA Modular Sling Back
ALPAKA Modular Sling | Think of it as an expansion pack for your other bags, too.

You can also use the Modular Sling as a pseudo-expansion pack for your backpack. It works well for that, and it’s even easy to attach, thanks to its built-in straps. That said, the vertical shape of the Modular Sling and its unbalanced interior layout detracts from its functionality as a sling. So, as with other travel gear, there are pros and cons to discuss here, and that’s what we’re doing in this review.

External Components

We usually avoid beginning this section of the review with aesthetics since we like to put more emphasis on practical features. However, this being an ALPAKA product, you can bet that the materials that make up the Modular Sling are more than just for show. See the diamond pattern? That comes courtesy of X-Pac fabric. To be more specific, it’s X-Pac VX21, which is a 210-denier nylon layer on the outside, followed by a thin polyester film, then the signature X-PLY, and, lastly, by a 50-denier polyester taffeta backing. It’s a well-engineered fabric, but what does it all mean?

ALPAKA Modular Sling Brand
ALPAKA Modular Sling | This rubbery matte material accents the X-Pac fabric.

Simply put, X-Pac is a rugged and waterproof fabric. Water must go through all those layers before they get to your gear. By the way, the sample we have here is the Black colorway, and it’s also available in Slate Grey. Both of which use X-Pac VX21, while the third colorway (Hot Orange) uses VX25. The main difference between the two is that VX25 has a polyester outer layer.

ALPAKA also went the extra mile and equipped the main compartment with AquaGuard YKK zippers to make sure your gear is well protected. We have to mention that ALPAKA sometimes switches the zippers they use without necessarily updating the specs indicated on their website. The sample we have here uses YKK. However, they may change to SBS, for example, in the future for various reasons.

You’ll also notice a lot of Hypalon-like rubbery material on the exterior of the Modular Sling. There’s some at the bottom of the front bearing the logo, on the zipper pulls, and on the straps at the back. These add a bit of accent coloring to the pack, and extra grip in the case of the zipper pulls.

ALPAKA Modular Sling Zipper
ALPAKA Modular Sling | These are YKK, though ALPAKA may source other brands of zippers.

Flip the Modular Sling around, and you’ll find overlapping straps. Two run horizontally, while the last one goes top to bottom. The first two secure via hook and loop, while the vertical strap uses a snap fastener. As you may have already guessed, these straps are for attaching the Modular Sling to other bags, hence the “Modular” in the name.

The overall build quality of the Modular Sling is completely in line with what we’ve come to expect from ALPAKA. As a reminder, this is the same brand that made a pouch barely larger than a credit card out of X-Pac. The material was a bit overbuilt for its size, whereas it’s more well-suited for the relatively bigger Modular Sling. It’s very structured, so it doesn’t feel floppy to carry nor too thin-skinned to reasonably protect the gear inside.

ALPAKA Modular Sling Back Strap
ALPAKA Modular Sling | Attachment straps make this sling an add-on module to other bags as well.

The main strap attaches via gatekeeper clips to the back, where there are two narrow loops of the same Hypalon-like material we discussed earlier. They’re also quite narrow, which can make inserting the clips tricky. Mind you, our main gripe with gatekeeper clips is that they’re usually very stiff, making it rather tricky to disengage them.

Fortunately, removing the strap isn’t something you’ll want to do regularly. The Modular Sling, surprise surprise, works best as a sling, so you’ll want to keep the soft, seat belt-like strap on 99% of the time. We’ve seen slings that use rougher or more course materials, which certainly make an impact on comfort. Suffice it to say it’s not something we take for granted.

ALPAKA Modular Sling Strapped In A Bag 2
ALPAKA Modular Sling | It’s like an expansion pack.

Speaking of features we appreciate—strap keepers! There’s one holding the strap segments that adjust together, thus stopping them from kinking and tangling. We absolutely dig it whenever companies include strap keepers because they keep the pack looking neat. Dangling and bunched-up straps are our pet peeve here at Pack Hacker, though some folks like the look of it, so we’ll leave it up to you if that’s your thing.

Fit Notes

ALPAKA Modular Sling Side By Side
Left: Tom Wahlin, Height: 6’2” (188 cm), Torso: 19.25” (49 cm) | Right: Lauren Maternowski, Height: 5’6” (168 cm), Torso: 16.5” (42 cm)

The Modular Sling doesn’t have the most sophisticated harness system, even among slings. In some cases, you’ll find others with compression systems, magnets, and even a bottle opener. That said, the simplistic strap ALPAKA provides here delivers suitable comfort for the Modular Sling’s size. Notice how those gatekeeper clips mount at an angle. The subtle design choice lets the straps split into a wide rounded shape natural to the human torso.

The Modular Sling isn’t the kind of sling that you’d wear close and across the chest like the Aer Day Sling 2 or Bellroy’s Venture Sling 6L. It sits a little lower, towards the side of the stomach or lower back, because of its narrow and downward shape. Gear tends to settle at the bottom, causing the pack to pull down naturally. If you prefer a more tight-fitting crossbody style, this might not be ideal for you, though it’s certainly comfortable if you’re just looking for a casual carrying style.

ALPAKA Modular Sling Strap
ALPAKA Modular Sling | Soft seatbelt-like material is a preferable choice for a strap.

Of course, you can also opt to attach the Modular Sling to another bag using the attachment straps at the back. In practice, though, it’s rather large to mount on a shoulder strap. Having it sit right in front of you is distracting and uncomfortable. However, if you plan to add it as a module to the side of your backpack, then it works just fine. Just be sure to secure the snap fastener properly and/or the hook and loop straps so that it doesn’t fall off by accident.

Inside The Sling

At the front of the Modular Sling, you’ll find a slip pocket with a magnetic flap. It’s fuss-free to use, for the most part, and we use it to store a Pro Max-sized iPhone 14. However, we found that when the main compartment’s packed out, tall devices like those are difficult to fit all the way to the bottom, making it hard to close the magnetic flap. It’s such a shame that it’s so close to being a perfect fit while, at times, falling short of just a few millimeters of clearance.

ALPAKA Modular Sling Cellphone
ALPAKA Modular Sling | This pocket can get a bit tight when the main compartment’s packed out.

As mentioned before, the Modular Sling has a very vertical layout, similar to that of the NOMATIC Access Pouch. Unlike that sling, though, the interior of the Modular Sling is much more organized. Starting with the way it opens, gussets at the sides provide wide access to the interior while ensuring the whole front doesn’t just fly forward. Those familiar with ALPAKA’s other products will feel right at home with those gussets. Oh, and the brand’s orange liner also makes an appearance here.

This bright liner makes finding gear inside much easier, especially considering the tall-and-narrow form factor. Trust us when we say it’s hard to hunt for a black micro SD card when your sling’s interior is also black. So far, so good, then for the Modular Sling.

ALPAKA Modular Sling Interior 2
ALPAKA Modular Sling | Orange liner is a big help to interior visibility.

As for the organization options, you have a bunch of pockets. At the back is a slip pocket big enough for a slim battery bank like the NITECORE NB10000. Alternatively, you can put a Pro Max-sized iPhone here, though accessibility isn’t as easy here as in the front pocket. There’s empty space in front of the slip pocket, and, across the way, along the front side, is where the bulk of the organization lies.

From the top, there’s a passport-sized slip pocket, then below that are two elastic loops that act as dividers for the single slip pocket even further below. It’s worth noting that these smaller pockets don’t use the orange liner, so if you drop anything dark and small there, you might have to take a closer look to find them.

ALPAKA Modular Sling Stuffed
ALPAKA Modular Sling | We wish that the upper space is better utilized by the organization.

All in all, it’s a healthy amount of organization for a sling this small. That said, we think it is too concentrated around the lower section of the Modular Sling, though your mileage may vary. A bunch of space is wasted around the top of this relatively tall sling. So even if you’re stacking a lot of gear, you will only be using some of that space. Worse, since the organization is focused around the lower areas, it can cause unnecessary bulging, leading to a tight fit for the front pocket and making it hard to close the magnetic flap.

Usage Timeline

Initial Usage


  • Interesting format for a sling—vertical—and dig the option to attach this to backpacks, too
  • Exterior magnetic flap closure is hindered if sling is too full
  • Left wanting a little more depth—even a max-sized iPhone on the outside and Airpods & battery bank on the inside can start to get pretty full depth-wise
2 Weeks of Use

Condition: Excellent

  • Sling is relatively narrow, especially when utilizing all pockets—it can be hard to zip up
  • Depending on what you carry, there may be some wasted space at the top
  • Nice comfortable wear that sits in a great position at the front of the body
  • Great materials
By Tom Wahlin
Created January 19, 2023 • Updated January 19, 2023
Access the Pro Community Discussion

Get your questions about the ALPAKA Modular Sling answered from our team and the Pro Community right here on the page. Plus, join discussions with other members about gear, guides, and more.

Join Pack Hacker Pro or, Sign In