This GR2 is built out of 420D ROBIC® Ripstop Nylon. What that means for performance is that it's super water-resistant and ultra-lightweight. The ripstop grid pattern increases tear strength for an overall better strength-to-weight ratio and it's got a special waterproof coating that's designed to last longer than traditional PU.
GR2 is a suitcase on your back. Pack everything you need and it still fits in the overhead compartment.