The Atom RE40 (Black)

Torso Size
Typically ships within 2 weeks

Perfect additions to The Atom RE40 (Black)

Removable Webbing Hipbelt (25mm)

Removable Webbing Hipbelt (25mm)



Aimed squarely at the ultralight hiker, the Atom gives you easy access to everything you need to keep hiking all day long using the five pockets that are easily accessible when worn.

This pack has few load assisting features and, as such, is only intended to be used by those with dialled in gear lists who like to enjoy the freedom of a light pack and moving without a frame or hip belt.

Load capacity
9kg / 20lbs max

Pack weight
438g / 15.41oz

Height fully unrolled
77.5cm / 30.5"

Circumference at base
79cm / 31"

Circumference at top
86cm / 34"

Main body volume

Side pockets volume
2 x 2.5L

The front pocket can stretch to hold up to an additional 5L in volume.


Dual shoulder pockets
Super stretchy and big enough to hold most smartphones, a day’s worth of snacks or a 700ml water bottle. The elastic is fixed and, owing to its clever design, does not need a tensioner.

Bottom pocket
Easy-access bottom pocket with trash port made with Dyneema stretch fabric.

Large front pocket
Made with Dyneema stretch fabric. Can hold 5L, not included in the total volume.

Side pockets
Two 2.5L forward-facing, deep and low side pockets made with 210D Robic Extreema. Each one is big enough to keep 2 x 1L Smartwater bottles steady, yet low enough to reach whilst the pack is worn.

Front zig-zag elastic
Removable and designed to be able to store a folded Z-rest or assist with air drying your clothes.

Side elastic with Lineloc
These are there to secure a pole or tent stakes when stored in the side pocket. If you are wanting to compress the bag, we recommend switching to a non-stretch cord.

Sternum Strap
Elasticated and height adjustable.

Trekking pole loop
Small, removable elastic toggle to connect walking poles or ice axe.


210D Robic Extreema

210D Robic Extreema


210D Robic Extreema
Side pockets and shoulder straps

Dyneema Mesh
Front pocket and bottom pocket

The Atom

A quick video run-through of The Atom

The Atom

Made for Movement

Aimed squarely at the ultralight hiker, The Atom gives you easy access to everything you need to keep hiking all day long.

Built with


210d Robic Extreema is one of the toughest backpack fabrics on the market.

The fabric is soft to touch and has a PU coating so is highly water resistant.

How to Choose

The Atom vs The Atom+

Which is right foryou?


Customer Reviews

Based on 9 reviews
Matthew Bailey
So much more than a great looking bag!

My first Atom Pack. I bought this pack 2 months ago to help reduce my spring/summer pack weight and have been nothing but blown away by the detail and thought of the design. Currently in the process of purchasing a custom MO60 for winter and i know ill be impressed yet again. Added bonus to be able to support another great UK maker. Thank you Atom Packs

Graham Horsley
So light & comfortable you don’t know its there!

I received a 40l Atom+ for my birthday - the all robic fabric one.
I used it for the first time on my 12 day crossing of Scotland in this year’s TGOC.
I didn’t notice the weight (9kg) at all until day 11! No sore shoulders!!
The pocket underneath the sac for food is brilliant.
An amazingly comfortable sack that is just big enough for all I need for a long trip.


I’m really impressed with the quality materials, fittings and impeccable UK manufacturing. The pack has the perfect balance of simplicity and yet equipped with considered and well thought out features - it’s a very well accomplished design. Atom were great to deal with and the various YouTube videos gave a great insight into their ethos, I’m happy to wear their pack with pride.

My standard Atom 35 in VX21 came in at 450g, but removing some of the optional bungees that I know I won’t need should see it down to ~425g which is hugely impressive given it’s capabilities.

Keep up the good work, I wish Atom every success.

Thank you.

Lightweight, yet sturdy

Too many of the other ultralight products I've purchased recently just haven't been durable enough to justify buying and using. I've used the 35L atom on many trips now and it's blowing everything else out of the water. It's been in the desert, swamp, and mountains and it's my favorite piece of gear.

The wide shoulder straps are not noticeable until you go back to a pack that has smaller ones. Then you will miss the wider straps. The pack itself is pretty narrow; narrower than I thought it would be, but it can still fit the smaller, blue bear canister in any orientation. The bottom pocket works well too.

I can get 5 days of food comfortably in the 35L, 6 if I am diligent. I love the pack for any trips less than a week. Anything longer would probably start to get a little uncomfortable.

John Skinner

Honestly the perfect pack, beautifully made with useful pockets in all the right places. Personal highlights are the shoulder pockets and bottom pocket.