Waterfly Ultralight Foldable Backpack 15L (140g) – packable daypack for hiking, travel and everyday outings

What it is and why it’s useful

This Waterfly Ultralight Foldable Backpack is a small 15L daypack designed to be folded up and carried without taking over your bag. On paper, that makes it the kind of packable rucksack you reach for when you want a bit of structure and storage, but you don’t want to commit space to a full-sized hiking bag.

The folding mechanism is also the big story: it packs down into a compact form that can be stowed in your suitcase, handbag, backpack or even the car. Then, when you need it, it unfolds into a usable daypack with space for the stuff you grab on the move.

It’s not trying to be a heavy-duty expedition pack. It’s more about practical, lightweight carry for day trips and day-to-day errands where convenience matters.

The essentials (folding size, weight and everyday comfort)

The folded size is stated as 15 x 15 x 3 cm, which is notably small for a backpack. When unfolded, the backpack measures 36 x 27 x 12 cm. If you’ve ever packed “just in case” gear and ended up regretting the bulk, this design is aimed squarely at solving that.

Weight is another clear selling point: the backpack weighs only 140g. That’s light enough that you’re unlikely to feel it much while you’re out.

For comfort, the shoulder straps are described as breathable mesh. That’s a sensible detail for warmer days or longer walks, where non-breathable straps can get sweaty.

Where you should keep expectations realistic: ultralight designs can only go so far in terms of padding and rigid support, so if you’re used to a structured hiking pack, this may feel more “light carry” than “proper load-bearing”.

Storage capacity and how the space is laid out

With a capacity of 15L, this bag is positioned for essentials rather than full-day kit. The description calls out room for items like clothes, water bottles, umbrellas and snacks.

There’s also a small back pocket intended for valuable small items such as cash, keys and bank cards, with an anti-theft style approach suggested by the pocket placement.

For day trips, that arrangement can be handy: you can keep valuables in the rear pocket and use the main compartment for everything else. A small example: say you’re on a city tour and you’ll pick up snacks and a small bottle of water along the way—15L is generally enough for that sort of “out and about” load without carrying a bulky bag.

Materials and build quality (what to look for)

The backpack is made from ripstop nylon fabric, which is described as helping prevent tears and moisture. Ripstop is a common fabric choice for packable gear, and it suits this backpack’s “fold, stash, unfold” purpose.

Durability details mentioned include SBS zippers and reinforcement with multiple stitching. Those aren’t guarantees of lifetime use, but they do suggest the brand has tried to avoid the typical weak points of very lightweight foldable bags.

If you’re shopping for something you’ll throw into a suitcase often, those practical build details matter more than you might think.

Usage ideas and practical limits

This is a multi-scenario daypack for short trips, city tours, walks, day hikes, small shopping and beach holidays. In other words, it’s meant for occasions where you want a lightweight rucksack that’s easy to bring along.

It’s also the sort of pack that works well when you’re travelling with only hand luggage or when you want the option of carrying extra items after you arrive.

Still, there are some limitations worth acknowledging. Because it’s described as ultralight and packable, it may not be the best choice if you regularly carry heavy loads, need strong suspension, or want a highly organised hiking pack with lots of compartments and features.

Quick comparison in your head (packable vs proper daypacks)

If you’re deciding between a packable daypack like this and a more “proper” day hiking rucksack, think about how you’ll use it most.

Choose a packable bag if convenience is your priority—something you can keep in your travel bag and deploy when you need it.

Choose a non-packable daypack if you expect frequent heavier carry, want more structure, or care more about detailed comfort and organisation than about folding into a tiny size.

This Waterfly sits firmly in the packable, lightweight bracket.

Who it suits best (and who should skip it)

It makes sense if you want an ultralight 15L daypack you can fold into your own inner pocket and store with minimal effort. You’ll likely appreciate the breathable mesh straps, the rear pocket for small valuables, and the fact it weighs just 140g.

It may not suit you if you plan to carry a heavy load every time you go out, or if you need a backpack that feels like a more structured hiking rucksack rather than a lightweight, packable alternative.

Is it worth it?

If you’re looking for a small, foldable 15L daypack for travel, city days and short outings, this Waterfly model is the kind of practical buy that earns its keep—especially because it folds down very small and stays very light at 140g.

It’s not the one to pick if your priority is maximum support, heavy carrying, or a highly featured hiking setup. But for everyday essentials—water, snacks, a small umbrella and a change of clothes—the combination of ripstop nylon, breathable straps and packable convenience is the main appeal.

FAQ

Will it fit in a suitcase or handbag when folded?

The folded size is listed as 15 x 15 x 3 cm, so it’s designed to pack away into carry spaces like a suitcase, handbag, backpack or car.

How big is the backpack when unfolded?

When unfolded, it’s described as 36 x 27 x 12 cm.

Is it heavy?

No—the stated weight is 140g, which is meant to feel very light on your back.

Does it have somewhere to store valuables?

Yes. There’s a small back pocket intended for small valuables such as cash, keys and bank cards, with an anti-theft style focus based on the pocket design.

What material is it made from?

It’s made from ripstop nylon fabric, with SBS zippers and multiple-stitch reinforcement mentioned for durability.