Shellback Tactical Flap Sac 2.0 Pouch The Shellback Tactical Flap Sac 2.0 Pouch is a multi functional general purpose pouch that provides load carriage and storage for mission specific gear. This pouch hangs under the front flap of most plate carriers and attaches quickly and securely via hook and loop. The Flap Sac 2.0 was designed to provide a fanny pack add-on to your armor carrier. The Flap Sac 2.0 features two alternating zipper pockets on the front and one zipper pocket on the rear.