600D, TPU laminated heavy duty waterproof fabric.UV resistant PVC free fabric withstands cold temperatures.Waist strap helps support the load when the pack is filled.Non-wicking TPU roll top closure with innovative interlocking profile that is secure and waterproof.Welded construction for permanently sealed seams.7075-T6 anodized aluminium buckles are robust and fail safe.Fully adjustable back length and height adjustable sternum straps, each linked to low profile attachment points to reduce snagging when harness is not attached