With a well-ventilated back panel to keep you cool and a superior suspension on the Gregory Z20, going light has never been so easy Jet Stream Direct Transfer Suspension puts the weight of the pack directly on the specially-designed frame, increasing support as the load increases. Zippered, hydration-compatible main compartment sports a sleeve with hanger for your reservoir sold separately. Front adjustable bungee cord lets you stash bulky gear and keep it easily accessible. Top pocket stores your portable music player and energy gels. Single pole-attachment point lets you strap on additional gear. Flexible Auto-Fit harness matches your shoulder angles perforated foam is covered with 3D mesh to vent and wick away moisture. 2 stretch-mesh side pockets keep your GPS, water bottles and snacks within easy reach. Constructed from 210-denier, high-tenacity ripstop nylon and nylon twill for tear strength and abrasion resistance.