The Atom Packs The Atom+ EP40 is a 40 L ultralight pack with a removable carbon fibre hooped frame and a padded back panel — a step up in comfort from the frameless Atom line. The body combines 200D EPX200 on the main panel, tougher 400D EPX400 on the base, and a stretch Dyneema front pocket, all closing via roll-top.
A base weight of 650 g at 40 L with a frame and padded hip belt is a solid ultralight figure — the comfort penalty over the frameless Atom RE40 (438 g) is roughly 200 g, a reasonable trade for better load transfer to the hips. One front pocket, two side pockets, and one ice axe loop cover the basics, though there's no integrated rain cover or hydration compatibility.
It's built for multi-day trekking and thru-hiking where the wearer wants to carry a bit more than the bare ultralight minimum while staying well under the weight of conventional trekking packs. The removable frame lets you shed further weight when the load is light.