Divide the main compartment when needed, or fold down the shelf for access to the entire space. A port door is built in for easy access to gear stored below the shelf. A padded compartment in the back of the pack holds your choice of a large laptop or hydration reservoir. The STAX 3-Day Pack is constructed of rugged 500D nylon and is built to hold up to 2100 cu. inches worth of gear. The size of this pack combined with padded waist belt to help with weight distribution and comfort, the STAX 3-Day Pack is great for any lengthy ruck.