Although it isn’t your run of the mill LE item, we had a chance to check the LBT Jungle Pack out at the ADS Inc federal range day.
It offers 2500 Cu In of internal storage with an internal frame (CASS) and removable lid (200 cu in) with mesh topped pocket. They’ve built a couple of different variants of the Jungie Pack that they’ve been supplying to operational forces which vary based on materials used and frame type. For instance, there are some ALICE frame models running around. This one, with the CASS frame (developed initially for body armor) weighs in right at 4 lbs.
This model is made from 330D Cordura and has a LiteLok expandable collar. All of the pack bags feature a flat, full length zipped compartment along the back of the bag but other than that, they are slick on the outside to make it easier to maneuver through thick brush.