The largest model in the Nimbus family, this load gobbling pack will carry all you need for long trips, or hold the gear needed for tackling the big mountains. Donât let the light weight of the pack fool you - the super rigid maple core framesheet and exoskeleton belt are built to handle the big loads. Granite Gear's 3D TopoFlex frame is engineered to fit the topography of your back and mimic the way a back naturally flexes. The single âPivot Pointâ attachment system on our shoulder straps and belts allows not only a more precise fit and enhanced freedom of movement; It supports and more equally redistributes your load along your hips, shoulders, and back! Now made with a maple-core, composite laminate which is both lighter and offers more longitudinal rigidity. Their Advection Back Panel compliments the ergonomic carriage benefits of the Topoflex gram and harness system by encouraging heat transfer and dissipation while simultaneously using the natural symmetry of the back.