Removable hipbelt can be custom molded for a perfect anatomical fit; it offers superior load support, stiffness and padding with dual-density foam for enhanced comfortOsprey-certified custom molding is available in most stores—check your local REI store for a custom hipbelt molding ovenDual-density foam harness with spacer mesh promotes airflow and wicks away moisture during warm weather and intense activitySuspension features a peripheral frame, smooth spacer-mesh back panel, single stay and an internal framesheetRunning down the sidewalls, the peripheral frame anchors to the load-lifter straps and hipbelt, transferring the load to your hips and resisting sagHDPE framesheet and a center aluminum stay protect your back from bulky or pointy items and support heavy loadsTop lid can be removed and converted into a lumbar pack; hipbelt can be removed from the pack and attached to the lumbar pack for comfortable carryingJ-zipper panel access on the front of the pack body makes stowing and accessing your gear a breeze, even when it's buried deep in the packExternally accessible bottom compartment with a wide mouth and divider accommodates all types of sleeping bagsZippered hipbelt pockets and stretch-woven side pockets keep essentials accessible; stretch-woven front pocket with welded vent accepts Osprey AddOns™ (sold separately)Compression system with 3 horizontal straps and 1 internal strap lets you securely compress the contents whether full or nearly empty, and without sag or load distortionTrekking pole attachment, side gear straps, ice axe tool loops, cord loop attachment slots and removable sleeping pad straps accommodate a variety of alpine gearHydration-compatible design features reservoir sleeve and dual drink tube exit ports for on-the-go hydration (reservoir sold separately)Osprey Aether 70 pack shaves weight yet remains tough with a 210-denier double-ripstop nylon and and 500-denier plain-weave oxford nylon bottom