Sea to Summit Hydraulic Packing Cube Review

Though they lack fancy bells and whistles, the Sea to Summit Hydraulic Packing Cubes are worthy travel companions that do far more than carry your clothing.

Our Verdict

7.2 /10
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  • Materials are durable and highly water resistant
  • Sturdy attachment loops stay out of your way when not in use
  • Cubes stow inside each other


  • Don’t compress or conform to your clothing
  • Zippers can be hard to open and close
  • Small cubes aren’t large enough for most clothing

Technical Details

  • Weight (oz)

    4.4 oz (124.7 g)

  • Dimensions

    5.5 in x 10.5 in x 4 in (14 x 26.7 x 10.2 cm)

    (large size) 4.25” x 8.25” x 3” (medium) 3.5” x 5.5” x 2.5” (small)

  • Notable Materials

    Thermoplastic Polyurethane (TPU), Ripstop Nylon, Hypalon®

  • Warranty Information

    Sea to Summit Warranty & Repair

Buying Options

Seatosummit Logo
Moosejaw Logo

Full Review

We’ve come to expect unique products from Sea To Summit, and these packing cubes are no different. They appear somewhat rigid, which is odd given their lightweight construction, and feel technical compared to other packing cubes we’ve tested. We’re amped to give these a go to see how well they handle clothing and whether we can stow other goodies inside, too. Let’s dive in!

External Components

The exterior material is 70D and has a PU coating on the zippers, adding water resistance to the cubes. There’s also some thermoplastic urethane, which is waterproof and semi-transparent. This makes it so you can see through the front window of the cubes, so you know what’s inside. It’s handy if you have multiple similar-sized cubes, as you can see what you’ve got stowed in each one. However, they aren’t completely clear, so if things are the same color, it can be confusing as to what is what.

Sea To Summit Hydraulic Packing Cube Medium
Sea to Summit Hydraulic Packing Cubes | We dig the design.

The materials are PFC and PFA-free, which is rad. The CDC says perfluorochemicals affect your health, and perfluoroalkyl and poly-fluoroalkyl substances can increase cholesterol levels, among other health risks.

The materials are extraordinarily lightweight. That said, they hold their shape reasonably well, even when empty. This helps when packing them out because you know what you’re working with and can slot your gear accordingly.

On the side, there’s a handle. You can use this to pull the cubes out of your pack or walk across the airport with some clothing to get changed after you arrive at your destination. The handle material feels like Hypalon. It has no padding but is comfortable enough to carry for short distances.

Sea To Summit Hydraulic Packing Cube 3
Sea to Summit Hydraulic Packing Cubes | The extra small, small, and medium packing cubes.

A small attachment eye on either side of the handle is a durable and handy way to make your pack more modular. You can attach them to your pack or on the exterior with a carabiner.

Choose from five different sizes, ranging from extra small to extra large. The three we have on hand—extra small, small, and medium—come in a pack together, though you can purchase any of the sizes independently.

The smallest two sizes are too small to use as a packing cube, but they’re worthy additions to your travel kit if your travel backpack or daypack doesn’t have much organization. Use them to stow the smaller bits and bobs you don’t want to get lost in the depths of your pack or store something like a set of Nanobag Reusable Shopping Bags inside so they don’t get caught on other gear.

If your sling doesn’t offer much water resistance and the skies call for rain, put the smallest pouch inside and throw your wallet and other small gear in it when the skies cloud up for extra protection. They aren’t waterproof but water-resistant enough to offer some protection.

Sea To Summit Hydraulic Packing Cube Brand
Sea to Summit Hydraulic Packing Cubes | The logo.

The smaller cubes open more like a toiletry bag than a packing cube. There’s a singular zipper that runs across the top of the pouch. When you get up to the medium size, the zipper runs around the outside of the cube, and it has a clamshell opening, which makes it easier to load clothing. Both zipper designs feel appropriate for their uses.

Inside The Cube

None of the cubes have any internal organization, but we weren’t expecting any. The inside is smooth and doesn’t get in your way.

Sea To Summit Hydraulic Packing Cube In Bag
Sea to Summit Hydraulic Packing Cubes | Sliding them inside the pack.

Because they hold their shape, they’re easy to pack, especially the larger cubes with the clamshell-style opening.

These aren’t the best packing cubes around because of the materials and hardware choices. They don’t compress, conform to your clothing, or have any extra bells and whistles. However, they work for much more than just packing cubes.

Due to their durability and water resistance, you can stow various travel products inside. The small cube is perfect for a toiletry pouch, given its size and top zipper. The handle makes it easy to head to the bathroom on the flight right before you land to freshen up.

Sea To Summit Hydraulic Packing Cube Large
Sea to Summit Hydraulic Packing Cubes | Loading gear inside the pack.

If you’re heading to a climate that has rapidly changing weather, you can stow one in your pack for after it rains. Once you remove your rain jacket, it will be wet, and you don’t want to let it dampen the interior of your pack. Instead, stow it inside the cube to keep things on the outside dry and remove it when you return to your hotel or Airbnb. The materials don’t hold moisture either, so you can wipe them down and be ready to use them again in a jiffy.

As mentioned, these aren’t the best packing cubes around. However, given what else you can do with them, they’re great travel companions. Whether you’re taking a road trip across the country or one-bagging it across Asia, they’ll come in handy!

Usage Timeline

Initial Usage

Condition: Excellent

  • Materials are extraordinarily lightweight, durable, and water resistant
  • Hypalon loops help attach the cubes to gear and add design flair
  • Hold their shape when you want them to; collapse down when you don’t
2 Weeks of Use

Condition: Excellent

  • Materials are extraordinarily lightweight but remain durable and highly water resistant
  • Zipper quality is high, and they do a swell job keeping water in or out
  • When not in use, you can stow them inside each other easily
By Eric Hergenreder
Created April 3, 2023 • Updated April 24, 2023
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