Osprey Eja Pro 55

The Exos Pro is Osprey's answer to the cottage ultralight brands: 33.2 oz for 55 L, or 30.4 oz with the lid removed. It uses NanoFly, a 100D nylon crossed with 200D UHMWPE, over a 3.5 mm LightWire frame, and saves about three-quarters of a pound against the standard Exos 58 at the cost of load rating and a fixed hipbelt.

The Exos 58 is Osprey's crossover ultralight — a sub-3-pound pack that keeps a real suspended-mesh frame and lifetime warranty. It has been an Appalachian Trail staple for a decade, and the current generation added an adjustable torso. The women's version is the Eja 58.

The Eja is the women's-fit Exos and Osprey's lightweight trekking pack: 2.8 lb for 58 L, with the same AirSpeed suspended mesh as the Atmos in a stripped-down chassis. It is the pack that bridges mainstream and ultralight, offering a frame and ventilation at a weight that cottage packs compete with.

The Atmos AG LT is the lighter reworking of Osprey's flagship Anti-Gravity pack. It keeps the suspended-mesh AirSpeed backpanel that made the Atmos famous but swaps the sliding harness for five fixed torso positions and drops to a 210D recycled honeycomb shell, saving around half a pound over the standard Atmos AG 65 and $50 off its price.

Aura AG LT 65 pairs Osprey's ventilated AntiGravity suspended-mesh back with a pared-down feature set, the women's counterpart to the Atmos AG LT 65. It weighs 4.0 lbs in WM/L (63 L WXS/S at 3.8 lbs) and carries 30-40 lbs. An integrated raincover, curved side zip into the main compartment, floating lid and internal hydration sleeve make up a simpler feature set than the full Aura AG.

The Atmos AG 65 is Osprey's flagship men's backpacking pack and the best-known application of its AntiGravity suspended-mesh suspension. The current generation adds more hipbelt padding, easier main-compartment access, and an included raincover. The women's equivalent is the Aura AG 65.