The Osprey Men's Exos 58 Pack is an ultralight pack designed for thru-hiking. Move fast through the trails, gathering up the miles with a lightness on your back. An AirSpeed™ 3-D tensioned back-panel vents while transferring the weight to your lumbar region. Go fully featured with this top-loader or strip it down to cut the ounces. The floating top lid is removable, as are the sleeping pad and side compression straps. The 58L (size medium) of space carries the gear to get you from section to section.