Versatility, a Girl's specific fit, and surprisingly large capacity for its weight (only 4 lbs. 9 oz. in medium), the Osprey Girl's Ariel 75 backpack is an excellent choice for climbers and backpackers who enjoy multi-day trips but want to keep the weight to a minimum. AirScape suspension consists of peripheral 7075 AL rods, an internal HDPE framesheet with single aluminum stay and a covering of ventilated nubbed foam and mesh grip. This covering, or backpanel, provides superb contact yet still allows air to circulate. Connecting to the suspension, a Girl's IsoForm custom moldable hipbelt and IsoForm shoulder harness with dual density foam and Spacer Mesh surface distributes the load evenly. Most Girl find that the harness and hipbelt that comes with the pack is the correct size for them, but other sizes are available for an exact fit.For those monster loads into base camp a stretch woven front pocket offers Additional carrying capacity when the main compartment is stuffed. And for go-light day trips from camp, the top pocket mates with the hipbelt to make a terrific lumbar pack. The Osprey Ariel 75 Girl's backpack is also Osprey Excessory compatible, meaning a choice of add-ons can be installed to further boost the backpack's versatility and capacity.