SpecTactical Wolfpack 65 - OD ABS (adjustable back system ) allowing you to chose the right height for your back and load Well padded lumbar back panel and Padded hip belt with fully adjustable shoulder straps and belt keepers for extra belt length Sculpted cross ventilation pathway to expel hot sweaty air for maximum comfort and breath-ability Inside removable aluminum frame Top-loading main compartment offers lots of room for your overnight gear plus bottom front loading for sleeping bag and easy access to main compartment