Aer City Sling 3 X-Pac Review | 2L Minimalist Sling for Everyday Carry (Is It Worth It?)

The Aer City Sling 3 in X-Pac is a compact 2L sling built for people who want to carry their essentials without committing to a full EDC bag. After using it during a day at a theme park with family, here is a detailed look at how it performs, what fits inside, and who it makes sense for.

Build and Materials

This is the X-Pac version of the City Sling 3, and the material is a big part of the appeal. X-Pac gives the bag a tactical, technical look and adds water resistance. As noted in the video, X-Pac has roots as a sailcloth material, so it resists water absorption rather than letting it seep through.

• X-Pac fabric for a sleek, urban-but-rugged aesthetic and water resistance
• AquaGuard zippers, an Aer-branded detail used across their designs
• Seatbelt-style strap material with conventional, classic buckles
• Padded top handle with double stitching and a bit of foam for comfortable grab-and-go carry

One honest note on quality control: the reviewer spotted loose threads in a few spots, including near the stitching and inside pockets. These are minor and trimmable, but worth flagging on a bag at this level.

A small gripe: the zipper pulls didn't win the reviewer over. They plan to swap them out, preferring simpler cord-style pulls.

Capacity and Organization

Aer lists this as a 2L sling. The reviewer suspects the real-world capacity feels closer to 1.5L, and points out that capacity measurements vary widely between brands. Either way, this is a minimalist bag meant for essentials, not a do-everything carry.

Front Pocket

The front pocket offers dual-access zippers, meaning you can open it from either direction. It's well suited to small, quick-grab items.

• Fits a phone (an iPhone 16 Pro Max with a Peak Design case slid in during rides)
• Good for keys, AirPods, a small power bank, and a short charging cable
• Handy for stashing a phone before hopping on a ride, then dropping the sling into a ride cubby

Main Compartment

This is where most of the volume lives, and it swallowed a surprising amount of gear during the theme park run:

• Hand sanitizer
• An Altoids-tin med case
• AirPods
• A Nitecore 6,000 power bank (the reviewer carried two)
• Vitamins, chapstick, and a microfiber cloth
• Lens/cleaning wipes

Inside are two Aer mesh pockets facing the front, which the reviewer praises highly for how well they hold and retain items. One larger mesh pocket held a stack of alcohol wipes. There's also a zippered pocket toward the back of this compartment that the reviewer hadn't yet used.

Fit testing showed the limits here:

• A passport-size notebook did not fit easily
• A Kindle can just barely fit, and only if the compartment is mostly empty

Rear Hidden Pocket

There's a hidden back pocket lined with breathable mesh, ideal for a wallet or passport.

• A passport slides in without issue
• A boarding pass fits without folding
• Note: this pocket is not RFID-protected, so add your own blocker if needed

The reviewer is a fan of hidden pockets in general and considers this a highlight of the design.

Comfort and Carry

The strap uses seatbelt-style webbing with standard buckles, and Aer advertises it for wear as a sling, hip pack, or chest carry. It worked as a chest rig during theme park use.

The main comfort caveat: strap length. At 5'11", the reviewer found the strap barely long enough, and went looking for an extender. Anyone larger may find the range tight, so the limited adjustability is a real consideration.

The padded handle, by contrast, is comfortable and well made.

External Carry Options

For a small sling, there are a good number of attachment points:

• Mounting spots compatible with an Alpaka-style system on both sides
• Hooks on the back and on the strap system

That strap-mounted hook is genuinely useful. You can hang the bag while in a restroom without needing a separate clip.

Who It's For

This sling makes the most sense if you want a minimalist, water-resistant carry for essentials, whether as a pocket-relief bag, an extended wallet, or a light day-out setup like the theme park use shown here. It's not built to replace a full EDC bag, and the reviewer still reaches for something larger when carrying a laptop charger and a journal.

Consider it if:

• You carry a phone, wallet, keys, AirPods, and maybe a power bank
• You want the tactical look and weather resistance of X-Pac
• You value hidden and mesh organization for small items

Look elsewhere if:

• You need to carry a Kindle, notebook, or passport comfortably alongside other gear
• You need a long strap or plan to wear it over bulky layers
• You want built-in RFID protection

The reviewer positions this against two similar minimalist slings worth cross-shopping: the Bellroy Venture Ready Sling at 2.5L and the Evergoods Civic Access Pouch / CAST 2 at 2L. Since brands measure capacity differently, comparing these three directly is the best way to judge which minimalist sling fits your needs.