In the world of ultralight backpacking, every ounce counts. That is exactly why Osprey Packs went back to the drawing board when creating its latest line of bags designed specifically for those who like to go light and fast on the trail. The newly updated Exos and completely new women’s-specific Eja packs are lighter than ever, without compromising on comfort and carrying capacity.

Both models are available in 38-, 48-, and 58-liter capacities, with weights ranging from 2.56 to 2.71 pounds for the Exos and 2.48 to 2.6 pounds for the Eja. The smaller of those packs is rated to carry 15 to 30 pounds, while the two larger models can hold 20 to 40 pounds. Both weight ratios are well within the “ultralight” category, which is generally defined by backpackers carrying loads of 28 pounds or less, including their tents, sleeping bags, stoves, and other gear.

In order to cut weight from these new backpacks, Osprey employed lightweight — yet strong — materials in their construction. Those materials include high-tenacity nylon integrated with an aluminum frame and a 3D-tensioned, breathable mesh back panel. Mesh fabrics were put to use only in the harness, however, but found their way into the hip belt as well, providing strength and durability, without adding bulk.

To further cut ounces, Osprey made it easier than ever for backpackers to customize these packs to fit their needs. Not only are the sleeping pad straps and compression straps removable, but the lid can be taken off too, stripping precious ounces in the process. Those are all items that ultralight backpackers tend to remove anyway, so making them optional was a logical step.

Other nice features include zippered pockets on both hips, trekking pole attachments that can be reached while still wearing the pack, and a hydration sleeve large enough to hold a three-liter water reservoir. Each of the packs also come with an integrated Flapjacket cover to provide protection from the elements when the lid has been removed, as well as removable ice ax attachments, and a sternum strap with an integrated safety whistle.

The updated Exos and new Eja backpack lines are now available. Prices start at $180 for the 38-liter versions, with the 48- and 58-liter models selling for $200 and $220, respectively. For more information, visit Osprey’s website.