Reach without rummaging
A quick-access front pocket, discreet rear valuables pocket and uncluttered main compartment keep the daily search short.
Flow Satchel · 2L / 4L / 10L
One shape.
Sized to your day.
Our curved Flow Satchel keeps your phone, bottle, tech and everyday essentials close—without making you carry more bag than the day needs.
4.6 / 5 from 262 reviews for our 4LLocal pricingChecking…
Checking your country for current pricing and availability.- 45-day returns*
- Lifetime warranty†
- Weather-resistant fabric
5,300+
original Kickstarter backers
4.6 / 5
from 262 reviews for our 4L
3 sizes
from light carry to laptop days
1%
of annual sales for the planet
Carry the day, not the clutter
Everything has a place.
Nothing gets buried.
We shaped Flow to sit naturally against you, then put the things you reach for most where your hand expects them.
Your bottle stays outside
The expandable sleeve holds your bottle away from the main compartment, with elastic retention to help keep it in place.
Curved for closer carry
The crescent-shaped body is designed to follow your side, with an adjustable, detachable strap across every size.
Find your Flow
How much day are you carrying?
Start with what needs to fit. We’ll take you to the right size; colour and material come next on our store.
4L
The everyday middle
Flow Satchel (4L)
Checking…
Our 4L is the versatile middle: enough room for an iPad mini, a light layer and a full-size bottle without moving into laptop-bag territory.
Made to fit
- iPad mini
- Light layer + daily essentials
- Bottle up to 8.5cm wide
Carry details
- 400–405g
- 80–140cm detachable strap
- Axoflux or X-Pac X42
Standard strap included. Optional padded strap is sold separately.
Shop the 4L on ALPAKAChecking your country for current pricing and availability.
Built around the reach
Small decisions.
A smoother carry.
Intuitive organization
Open. See it. Grab it.
The wide top opening and flexible internal layout give your gear breathing room, while separate quick-access and valuables pockets handle the small things.
Hydration on the go
Carry the bottle, not the leak anxiety.
The external expandable sleeve fits bottles up to 7.5cm wide on 2L and 8.5cm on 4L and 10L.
Ready for changing weather
Built to shrug off the everyday.
Recycled, PFAS-free Axoflux fabric is weather-resistant, with AquaGuard zipper use where the design calls for it.
Flow from every angle
See how it carries.
See what fits.
Five quick looks at the shape, access and everyday details. Choose any video to play it with sound.
The original Flow in motion
See how 2L and 4L sit, open and move.
This official walkthrough shows the original Flow shape, bottle sleeve and access system in action. The newer 10L keeps the same design logic with room for a 13-inch laptop.
Compare all three sizes
Size, without the guesswork
Three sizes. Three kinds of day.
| Size | Best for | Device fit | Weight | Strap | Price |
|---|---|---|---|---|---|
| 2LLight carry | Phone, small e-reader, slim bottle and daily essentials | Small e-reader | 300g | Standard | Checking… |
| 4LEveryday middle | Daily kit, light layer and bottle up to 8.5cm wide | iPad mini | 400–405g | Standard‡ | Checking… |
| 10LFull-day carry | Laptop, tech pouch, bottle and the full daily kit | 13-inch laptop | 677g | Sliding pad included | Checking… |
‡ The removable padded strap for 2L and 4L is sold separately. Product pricing and availability can change; our store shows the live local offer.
Size-specific proof
The right size is the feature customers notice.
“Perfect size. Great compartments and organization.”
“Love this bag. Perfect for short trips.”
Ratings and review counts are shown for each product size separately and may grow over time.
Days to decide
Eligible, unused website purchases can be returned within 45 days of fulfillment. Conditions and return costs apply.
Lifetime warranty
We cover manufacturing defects for the life of the product, with repair as the first remedy where possible.
For the planet
We donate 1% of annual sales to environmental organizations through 1% for the Planet.
The final checks
Before you pick your Flow.
Size is the biggest decision. These are the details that usually settle it.
Which Flow Satchel size should I choose?
Choose 2L for a phone, small e-reader, slim bottle and light essentials. Choose 4L when you want room for an iPad mini, a light layer and a full-size bottle. Choose 10L when a 13-inch laptop and a fuller daily kit need to come too.
Will my drink bottle fit?
Our expandable external sleeve fits bottles up to 7.5cm in diameter on the 2L, and up to 8.5cm on the 4L and 10L. Bottle shape matters as much as volume, so checking the width is the safest guide.
Is the shoulder strap padded?
The 2L and 4L include an adjustable standard strap. A removable padded strap is available separately. The 10L includes an adjustable sliding shoulder pad.
Is the Flow Satchel waterproof?
No. We use weather-resistant fabric and AquaGuard zipper construction where specified, but the bag is not waterproof or designed for submersion. The 10L also uses standard zippers in parts of its construction.
How do returns work?
Eligible website purchases can be returned within 45 days of fulfillment when they are unused, unworn, tagged and in original packaging. Original shipping, return postage, transaction fees, duties and taxes are generally not refunded. Final Sale and Outlet exclusions apply. Read our full returns policy.
What does the lifetime warranty cover?
Our lifetime warranty covers manufacturing defects. It does not cover normal wear, misuse or damage after delivery. We assess each claim and prioritize repair before replacement or store credit. Read our full warranty.
Which price will I see?
We're checking your country so we can show the current regional price. Our store confirms taxes, shipping and live availability before purchase.
Ready when your day is
Pick the size.
Keep the flow.
Light essentials, everyday carry or laptop days—start with what needs to fit.
Find your size