Disclaimer
Aer provided me with the Travel Pack 4 ahead of the official release for review purposes. No money exchanged hands, but I do get to keep the bag. The opinions in this review are entirely my own; Aer does not get to see this post before it’s published.

Aer Travel Pack 4 (35L) in 1680D Cordura ballistic nylon. I’m 173 cm, 66 kg (5’8”, 145 lbs).

Introduction

Aer is a San Francisco–based brand that has been making bags since 2014. It’s one of the favorites in the carry community thanks to the brand’s dedication to using advanced, high-quality materials and its focus on comfort.

The Travel Pack 4 is the next iteration of the backpack designed to be a carry-on. It comes in two sizes (28 liters, 35 liters), multiple fabric options (1680D Cordura ballistic nylon, VX-42 X-Pac, Ultra400X), and color options (black, navy, and olive).

The version I have is a 35L in black 1680D Cordura ballistic nylon. It retails for $259 USD.

Experience

The Travel Pack 4 is my second Aer product after the Day Sling 4. As a travel pack, I have not used it every day; instead, I took it for a comfort stress test and used it on a weekend trip.

For the comfort test, I loaded the TP4 to a total weight of 9.5 kg (21 lbs) with regular travel items: a MacBook, two packing cubes of clothes, toiletries, a CAP2 with stationery and tech accessories, a rain jacket, an umbrella, a water tumbler, a Kindle, a notebook, a power bank, etc., and took it for a 2-hour walk in the park (roughly 7,000 steps, according to the iPhone app). Despite the weight, the bag had proved comfortable, which I found reassuring for travel.

My weekend trip was from Chiang Mai to Pattaya via Bangkok. I flew with Thai Vietjet Air, a low-cost airline, and had no issues taking the TP4 on board, as it is within the airline’s size restrictions of 56 by 36 by 23 cm (22 by 14 by 9 in), and I had it packed to 5.5 kg (12 lbs).

Aesthetics

In terms of looks, it’s very much Aer. In fact, it’s so much Aer that the Travel Pack 4 looks like a scaled-up version of the widely popular City Pack Pro 2. For the most part, I like this, but the tapering toward the bottom, combined with the large size, makes the Travel Pack 4 resemble Dracula’s coffin in my opinion.

Despite that humorous comparison, I genuinely like the material and overall design. The 1680D nylon gives the bag a sleek, structured, and sophisticated look, which contrasts sharply with the huge, touristy backpacks seen in airports around the world.

All in all, the TP4 nails that balance between looking good and being super functional, showcasing the smart design that Aer is known for.

Dimensions, Volume, and Weight

Travel Pack 4 measures 54 x 34 x 23 cm (21 x 13 x 9 in). I don’t have the tools to double-check the volume, but One Bag Travels has verified that the Travel Pack 4 has exactly the 35-liter capacity as stated by Aer.

In terms of carry-on compliance, the TP4 35L is compliant with 73% of airlines. It’s a great score, but do check the requirements of the specific airlines you are flying with, and if you want something more universal, check out the smaller 28-liter version, which boosts the compliance score to 95%.

Now, the big elephant in the room: the weight. The Travel Pack 4 weighs 1.7 kg (3.75 lbs). I generally don’t mind heavy bags for daily carry, but it’s a travel bag, so airlines’ weight restrictions need to be taken into account. And when you only have 10 kg (22 lbs), or even 7 kg (15 lbs), to work with, having the bag take up a quarter of that might be a tough pill to swallow. Add another 3 pounds of an average laptop, and it’s looking even bleaker. So, do consider what you are usually packing before making a purchase.

Organization

The Travel Pack 4 is split into five sections: the back compartment, the main compartment, the front admin pocket, the front zippered pocket, and the top pocket. Let’s go through them.

Back Compartment

The back compartment features a 32 cm-wide (12.5 in) opening. Inside, there is a 30 cm deep slip pocket, perfectly sized for A4 papers, so they are right there without having to dig through. The laptop sleeve is lined with a soft, microfiber-like material on one side and protected by a padded divider on the other. It has 5.5 cm (2.1 in) of false bottom, making the sleeve 45 × 32 cm (17.7 × 12.5 in). Between the laptop sleeve and the slip pocket is an empty space that runs across the whole compartment, making it 54 × 32 cm (21 × 12.5 in).

Top Pocket

The top pocket is accessed via a 21 cm-wide (8.2 in) opening, is made of a soft, stretchy material, and has surprising volume. It easily fits a wallet, a power bank, a 35W MacBook charger, a charging cable, mints, and AirPods. The pocket is horizontal and takes only the very top of the main compartment, the part least likely to be packed out.

Main Compartment

The main compartment opens vertically in a clamshell style. There is a document sleeve with an elastic band on the back and two pockets on the front. The top pocket is 25 × 14 cm (9.8 × 5.5 in) and is made from a stretchy material; the bottom pocket is 27 × 24 cm (10.6 × 9.4 in) and is lined with a non-stretchy material. Additionally the top pocket features a loop for a keyleash and a hidden AirTag slot.

The packing cubes in the photos are from Muji. The black one is Medium and the green one is Small. Links are not affiliate and provided for reference only.

Front Admin Pocket

The front admin pocket features a 24 × 18 cm (9.4 × 7 in) non-lined slip pocket, a 23 × 17 cm (9 × 6.6 in) non-lined zippered pocket, and two soft elastic slip pockets: the smaller left one is 10 × 11 cm (3.9 × 4.3 in), and the bigger right one is 17 × 11 cm (6.6 × 4.3 in). Additionally, there is a pen pocket and a key leash attachment point. This pocket can fit quite a few things you want quick access to.

Front Zippered Pocket

Below the admin pocket, there is a zippered front pocket. It runs 24 × 31 cm (9.4 × 12.2 in). While it does have some independent volume — I can fit a packable sun hoodie and a packable tote — accessing the contents is difficult, as the opening is very tight.

Side Pockets

On both sides of the Travel Pack 4, there are side pockets made out of elastic material. At the tallest point, the pocket is 30 cm, and at the shortest, it’s 20 cm (11.8, 7.8 in). Height-wise, it can easily accommodate even a large 1-liter Yeti bottle, but it is tight when the bag is packed out. If you carry taller things, like a tripod, you can use the D-ring and a carabiner to secure them.

Additional Features

Luggage pass-through on the back, secured by a piece of velcro so it does not get in the way when you are not using it.
Hypalon latch points on the shoulder straps, plus a D-ring on the right shoulder strap.
Four handles all around the bag. The top handle and side handles have a thick layer of padding; the bottom handle is just a quick-grab point. This abundance of handles is useful on a travel bag, as no matter where it is — overhead bin, trunk of a car — you will always have a grabbing point.
Lockable zippers on both the main and back compartments.

Putting It Together

The Travel Pack 4 is impressively well-organized without feeling overly complicated. I particularly appreciate the layout of the back compartment, with its inclusion of a documents slip pocket and a solid false bottom for laptop protection.

The top pocket is one of the best implementations I’ve seen — generous volume, easy access, and tucked into space that wouldn’t otherwise be used. Combined with the front admin pocket, it gives the bag easy top-down access, which is very useful on a travel bag for quickly grabbing things from the overhead bin.

The admin pocket itself is thoughtfully laid out with a good mix of pocket types, and the main compartment is cavernous with practical organization on the front panel.

However, the front zippered pocket is disappointing, as its tight opening makes it less user-friendly despite the decent internal volume.

Materials, Hardware, and Build Quality

The exterior 1680D Cordura ballistic nylon is excellent — easily my favorite after trying it on the Aer Day Sling 4 and Able Carry Daily Plus. It’s tough, looks sharp, and feels smooth to the touch.

Inside, the bag’s lined with high-viz ripstop nylon, and all the stretch pockets are soft with a nice hand-feel. Handles and straps use smooth, high-quality seatbelt-style webbing.

YKK zippers throughout, though the experience varies by compartment. The laptop pocket and front pocket have PU-coated zippers; the others don’t.

To offset the difficulty of opening the front pocket and the main compartment, Aer has sprinkled latch points around the bag. Additionally, the zippers feature long, grippy zipper pulls.

Overall build quality is excellent throughout the bag: all stitching is immaculate, there are no loose threads, and bartacks reinforce potential weak points.

One note on the side pockets: the material feels great and is actually thicker than I expected, but it is still a soft material on the exterior of the bag. My concern is that if the bag does get checked in, the side pockets will be the first to get damaged. It’s not a well-founded, experience-based concern; it’s just a personal opinion, so take it as you will.

Comfort

Despite the heavy weight, the Travel Pack 4 is very comfortable. Well-contoured shoulder straps are 7 cm (2.7 in) wide and feature 1.5 cm (0.6 in) of well-ventilated padding. The back panel has a solid 1 cm (0.4 in) of padding made of a breathable mesh. Load lifters and the sternum strap help distribute weight extremely well. After walking for 2 hours with a 9.5 kg (21 lb) bag for my little stress test, I didn’t have any shoulder, neck, or back pain, and I am someone who often suffers from neck pain and carries Ibuprofen everywhere I go.

I also want to highlight the very plush — almost 1 cm (0.4 in) — carry handles. Whether it’s walking through a narrow airplane aisle, putting the bag in the overhead bin, or taking it out of the taxi trunk, the handles were comfortable and easy to grab.

For additional comfort, Aer offers optional hip belt that can be purchased separately.

Overall, the Travel Pack 4’s comfort is one of its best points, and I’m genuinely surprised by how well it carries.

Pros and Cons

Pros

Excellent comfort despite the weight, thanks to plush handles, shoulder straps, and back panel, plus load lifters and a sternum strap that all work together.
Premium 1680D ballistic nylon exterior, with interior materials, hardware, and overall build quality that don’t fall behind.
Smart organization, with a purposefully designed back compartment and cavernous main compartment. Easy top-down access via the top pocket and front admin pocket — very useful on a travel bag for quickly grabbing things from the overhead bin.
Four well-placed handles, including plush top and side handles.
Lockable zippers on both the main and back compartments.

Cons

Heavy. Even if comfort makes up for it, 1.7 kg (3.7 lbs) accounts for a large portion of carry-on weight limits (7–10 kg, 15–22 lbs).
Inconsistent zipper experience. The main compartment zipper is especially disappointing compared to the smooth zipper on the admin compartment right beside it.
Front zippered pocket opening is too tight, making access difficult despite decent internal volume.
Soft side pocket material — potential vulnerability if the bag gets gate-checked.
Coffin-like shape. The tapered bottom and large size create an unfortunate visual resemblance that some people might not be able to unsee.

Conclusion

Despite my nitpicks, the only true potential dealbreakers are weight and dimensions. If those work well for your packing style and the airlines you fly with, the Travel Pack 4 delivers excellent comfort, smart organization, and premium materials, making it one of the best travel packs out there.

Review: Aer Travel Pack 4 (35L)