G4Free Military Army Tactical Molle Backpack Multifunction mountaineering Hiking Trekking large capacity backpack (75L) (Black) Material: 600D polyester fabric, Waterproof, use High quality PU coating, more flexible Multi-panel Airflow ,U shape aluminum tube framework + HDPE elastic plate,strengthen the weight loading ability for cross-country and exploration activities ;Improve the supporting strength of backside support,release pressure of shoulder and make your back more comfortable High expansion capability :There are many connector and mount point on the bag ,convenient to attach with other small bags Open the large main pocket Longitudinal,when you need to take out or put in Large equipment's ,you will feel more convenient and efficient Widen Shoulder straps ,detachable WAIST SUPPORTER consist of High density foam & Elastic plate ,strengthen the braced force