The Sky 5900 blends function of a front panel zip with the versatility of the proven Sky design. The Sky 5900 weighs 5.55lbs on a Medium Xcurve Frame. The large front panel zip allows quick access to virtually the entire pack while the Sky design offers excellent compression. The Sky 5900 can go from a 4,300 cubic inch bivy mode to a full volume of 5900 cubic inches with the Sky Lid. Add the load shelf volume of 2,500+ cubic inches to bring the overall max volume to 8,000 cubic inches. Anything from day trips to extended trips, the Sky 5900 has you covered.