NcSTAR VISM Tactical 3 Day Back Pack Main Compartment 20"Hx11"Wx8"D (1870 cubic inches). Expandable bottom Pouch unzips to Dimensions of 6"Hx11"Wx8"D (528 cubic inches). Rear Compartment for hydration bladder (bladder not included). Pals webbing on the Front and Sides allow you to add any additional gear or pouches you may want to take with you. Main Compartment 20"Hx11"Wx8"D (1870 cubic inches). Expandable bottom Pouch unzips to Dimensions of 6"Hx11"Wx8"D (528 cubic inches). Two Side Compartments 14"Hx7"Wx3"D. Rear Compartment for hydration bladder (bladder not included). Pals webbing on the Front and Sides allow you to add any additional gear or pouches you may want to take with you.