The Osprey Aether 85 is the top-end model in the lightweight Aether series of men's mountaineering backpacks. Available in three colors and three sizes, the 2010 Aether 85 introduces several new features. The top pocket can be removed and converted into a lumbar pack, and built-in cord loops allow certain Osprey daypacks to be attached. Other key features include an internal compression strap, removable sleeping pad straps, and hydration system support for reservoirs up to 3 liters. The same features are available for women in the Ariel Series and in smaller versions in the Aether 60 and 70.