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Aer Day Sling 3 Max Review

The Aer Day Sling 3 Max has a large capacity for holding lots of gear, but some of the organizational features feel lackluster in its large size.

Our Verdict

7.9 /10
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  • Ample space to stow gear
  • Strap fastener placement is easy to find
  • Materials can defend against rain and mud


  • Lack of internal organization affects packability
  • Fidlock fastener takes some getting used to
  • A bit bulky for some applications
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Technical Details

100 %

Carry-on Compliance

View 145/145 Airlines

32 %

Like the Look

Polled on Instagram

  • Capacity


  • Weight (lb)

    1 lb (0.5 kg)

  • Dimensions

    12 in x 9 in x 3.5 in (30.5 x 22.9 x 8.9 cm)

  • Notable Materials

    CORDURA® Ballistic Nylon, YKK Zippers, Duraflex Hardware, X-Pac, CORDURA® Nylon

  • Warranty Information

    Aer Lifetime Warranty

Full Review

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We’ve reviewed as many Aer products as we have been able to get our hands on, but the Day Sling 3 Max is a first for us. It’s a larger version of the regular Day Sling 3, coming in at 6L compared to its smaller counterpart’s 3L.

Aer Day Sling 3 Max Side
Aer Day Sling 3 Max | Aer here, Aer there, Aer everywhere!

We’ve reviewed products with two different sizes in the past, and they tend to go one of two ways. The better of the two options is when they’re similar products but have unique features and organization that make sense for the pack or sling of that size. The lesser of the two options is when one is simply a larger or smaller version of the other—the same design, organization, and features, just a different size. This typically makes one of them feel clunky, no matter how well designed the original is. With that in mind, let’s take a look at how the Day Sling 3 Max fares.

Materials & Aesthetic

Believe it or not, this pack is made from a pile of truck tires Aer found behind their warehouse. We’re only kidding; it’s made from their staple material: 1680D Cordura ballistic nylon. It feels as durable as a truck tire, though, which is great for your more rugged adventures.

Aer Day Sling 3 Max Studio
Aer Day Sling 3 Max | The back blends in or can add a nice contrast.

In addition to being extremely tough, the 1680D is now bluesign approved, which means that it’s sustainably sourced. Aer is behind some of our favorite travel backpacks and slings, and knowing that the products we love come from sustainable means is excellent.

The fabric is also great at keeping water at bay. Even after 30 minutes of consistent light rain on the way to work and 30 minutes on the way home after the rain turned into sleet, all our gear was still safe and dry inside.

Aer Day Sling 3 Max Material
Aer Day Sling 3 Max | Textured to the max!

The colorway we have on hand is black and is sleek, minimalistic, and satisfyingly industrial. There’s also a Black X-Pac version and Heathered Gray version. The X-Pac has a little more shine and is great if you want additional weatherproofing. The interior for the X-Pac model is orange, which we dig for its added visibility. The Heathered Gray model is only 700D Cordura compared to the 1680D of the Black model we have on hand. Still, the fabric contrasts nicely with the black zippers and is a great way to switch things up from the usual black.

We see the integration of YKK zippers throughout the pack. The front pocket has a YKK #10 AquaGuard zipper, which we’ve come to expect on many Aer packs. The main compartment zipper is a YKK #8 zipper and is smooth and easy to operate. The front zipper is beefier than the main compartment zipper, which contributes to Aer’s signature design style. The hidden back compartment has a YKK #5 zipper that opens smoothly and quickly.

Aer Day Sling 3 Max Zipper
Aer Day Sling 3 Max | Added protection from the elements.

The zipper pulls start with a paracord material and end with a larger piece of hard cylindrical plastic. The end can get a bit slippery when wet, but it’s easy enough to grab onto where the cord meets the hard plastic in inclement weather. There are also two loops on each side of the front compartment zipper that assist in opening.

The strap has a Fidlock magnetic fastener. It’s two and a half inches wide (6.35 cm) by just under two inches tall (4.8 cm) and is about a quarter-inch (.635 cm) thick. It’s not in the center but instead closer to where the left side of the sling meets the strap. This makes it so that the fastener isn’t underneath your bag, pressing into you uncomfortably when you’re wearing it with a backpack. Plus, it’s easier to access if you prefer to unbuckle the strap every time you take off the sling.

Aer Day Sling 3 Max Fidlock
Aer Day Sling 3 Max | The Fidlock takes some getting used to.

We prefer standard side-release buckles because they’re more secure and just as easy to use. The Fidlock magnet is strong, but it can come undone at certain angles, causing the sling to fall off entirely. It doesn’t happen often, but it’s an issue we don’t have with more standard buckle designs. We found this more of an issue with the regular Day Sling 3, but it’s still an issue nonetheless.

As for other hardware, there’s a Duraflex adjuster on the strap that allows you to extend or constrain the length. It works as it should and feels durable. When fully expanded, the strap measures 52.5 inches (1.3 m), and when tightened as short as possible, it measures 30 inches (76.2 cm).

External Components

Aer Day Sling 3 Max Side by Side
Left: Lauren Maternowski, Height: 5’6” (168 cm), Torso: 16.5” (42 cm) | Right: Eric Hergenreder, Height: 6’0″ (183 cm), Torso: 18.5” (47 cm)

Sticking with strap talk, the Day Sling 3 Max follows in its little sibling’s footsteps and has a sturdy nylon strap that hasn’t shown any signs of fraying but can be uncomfortable with a sling of this size. This is especially true if you are wearing clothing that allows it to contact your skin directly, like a thin t-shirt or tank top. There isn’t any additional padding or aeration, so it can get a little warm, too. It isn’t overly wide, so the heat is concentrated in a small area and can make for awkward sweat lines.

The sling’s large size can also make it unwieldy to wear, but it’s comfortable once you find the position where it fits best, whether that’s on the front or back.

Aer Day Sling 3 Max Strap
Aer Day Sling 3 Max | It’s on the bulky side.

On the right side, is a small loop where the strap connects to the sling’s body. You can use this to hang the sling on a hook, but we found it to be a great place for a carabiner like the Nite Ize S-Biner. Or, hang it from a restaurant or coffee shop table using the Heroclip Hybrid Carabiner Clip. However, it’s worth noting that the strap does dangle a little awkwardly as it doesn’t stow away. It’s nice to be able to keep your eye on your gear, though!

As for the back panel, there’s not much padding to be found. There’s a bit between the rear hidden pocket and main compartment, though it seems like to protect gear rather than offer comfort. The Cordura has a little cushion, but there isn’t any mesh or aeration to provide airflow.

Aer Day Sling 3 Max Back
Aer Day Sling 3 Max | Cordura on Cordura!

On top of the back panel is a quick access handle toward the top of the sling. This handle is crafted from a much softer material than the shell and strap and has more padding than the handle on the regular size Day Sling 3. It isn’t very wide, but the softness and padding add comfort. The handle is an excellent addition for trips through the security line at the airport, as you don’t have to awkwardly hold the strap or quickly remove the sling when you get to the front of the line. Just hold onto the top handle and drop it into the bin, head through, and grab it by the handle again once you’re through.

Inside The Sling

There are a few pockets to discuss, but, we’ll start with the rear zippered compartment on the back of the sling. This flat pocket is the perfect place for a passport or other important documents you want to keep safe while exploring an unfamiliar place, as it’s well-hidden. If you didn’t know this pocket existed, you might not even notice that it was there, especially while the sling is on.

Aer Day Sling 3 Max Pocket
Aer Day Sling 3 Max | The perfect spot to hide your passport.

That said, you can still feel larger items through the pocket, even gear as simple as a phone with a bulkier case. It isn’t uncomfortable, but it is noticeable. As we mentioned before, there isn’t any padding between this pocket and the exterior, though there is some on the main compartment’s side. This keeps your passport and other travel documents relatively wrinkle-free, as items in the main compartment can’t bulge into them as easily.

The front zippered pocket is better suited for flat items, but there’s a little more space for larger gear compared to the hidden pocket. There isn’t much flex in the Cordura shell, so most of the room is shared with the main compartment. This can make it hard to get items in and out when the sling is fully packed, but it’s still usable either way.

Aer Day Sling 3 Max Cellphone
Aer Day Sling 3 Max | More than enough room for a phone and a few extra goodies.

It has a key ring similar to that of the regular Day Sling 3. However, we do find that when the main compartment is stuffed with oblong-shaped items, our keys can fall into cracks and crevices created by the things pushing into the front pocket. With the keyring, it’s easier to find them, but they can get caught on the fabric on their way out.

Moving into the main compartment is…well, a little daunting. It does have some organization, but it’s largely a free-for-all. To our eye, the interior is identical to the regular size Day Sling 3, just larger.

Aer Day Sling 3 Max Empty Interior
Aer Day Sling 3 Max | Look at all that room!

The front side has two elastic liner pockets that are mirrored on the backside as well, just a little wider. The elastic mesh is springy and tight enough to keep smaller items like phone cables, dongles, and headphones stuffed inside nicely.

On the back wall just above the wider mesh pockets is a zippered pocket. This is the only space in the main compartment with total security, as even with tight elastic, items can still bounce out. The zippered pocket is a great place for loose change, important cards and documents for traveling, or any smaller items you don’t want to end up in the commotion on the main compartment.

Aer Day Sling 3 Max Stuffed
Aer Day Sling 3 Max | Everything you need for the day, with room to spare.

Behind the elastic pockets and the zippered pocket is a large liner pocket. This is probably the high point of the main compartment, as you can fit up to an 11-inch tablet here. Our 9.7-inch iPad fits with room to spare, and a Nintendo Switch also feels very at home.

Bringing a larger tablet is perfect for trips where you aren’t planning to work but want the option to be still able to answer emails, watch movies on Netflix or Hulu, and keep up with the latest Pack Hacker videos on Youtube.

The backside of the large liner pocket is padded, as mentioned earlier. When there’s a tablet or electronic device in the pocket, it protects that device from being poked from the backside, but there is no such padding on the internal wall. Because of this, we face our devices glass outwards onto the back panel, which feels counterintuitive, though we haven’t had any issues with damaging devices.

Aer Day Sling 3 Max Tablet
Aer Day Sling 3 Max | Tablet space for days!

Other than the four elastic pockets, the zippered pocket, and the tablet area, the rest of the main compartment is wild for the taming. Coming in at 6 liters, there’s a ton of room to work with, but it can feel wasteful depending on what you plan to bring with you.

If you have any electronics, it muddies the waters. Do you place them on the bottom of the compartment and stack other items on top of them? Or do you stack your other items on the bottom and then place your electronics on top, not on flat ground? Things get sticky when you have expensive equipment, like a camera and a lens to bring along.

Aer Day Sling 3 Max Camera
Aer Day Sling 3 Max | Not a bad place for your camera gear.

We easily fit a Fuji X-T3 with a 15-45mm lens, an additional telephoto lens, and an Instax Mini inside the main compartment. There’s room leftover, but we’re hesitant to stow too much in case something gets damaged. However, this isn’t a camera sling like the Peak Design Everyday Sling, so we can’t fault it too much for something it’s not designed to do.

Even without electronics, the large main compartment can be problematic. With lots of smaller items, it can be hard to find things at the bottom. There’s a ton of space to work with here—if you aren’t organized, it can become chaotic quickly. The use of smaller pouches and organizers are helpful and make the sling more useful, but it’s up to you to decide whether or not you want to add your own.

Aer Day Sling 3 Max In Use
Aer Day Sling 3 Max | Time to hit the dusty trail!

Overall, the Aer Day Sling 3 Max is a competent sling that can carry a ton of gear. The materials shine here, as is often the case with Aer products. The main compartment feels a little lacking when it comes to organization, but there’s enough room to add your own if needed. There aren’t many changes from the regular-sized Day Sling 3 to compensate for the sheer amount of space this pack bolsters, but at the end of the day, it will get your gear from point A to point B—it just might take a while to find what you need once you arrive.

Usage Timeline

Initial Usage

Condition: Excellent

  • Large enough to fit an 11-inch iPad Pro with an Apple Pencil 2 attached
  • Still feels very structured despite the size boost
  • Magnetic Fidlock buckle feels satisfyingly tactile to use
2 Weeks of Use

Condition: Excellent

  • Zippers remain easy to open and close
  • Exterior still looks brand new
  • Back panel isn’t very padded
By Eric Hergenreder
Created March 21, 2022 • Updated September 26, 2022
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