It's pretty simple: if you have a Micro Fight Chest Rig, you're going to need this. The Back Strap provides the retention necessary to keep the Chassis close to your body. The back strap attaches to the lower buckles on your Micro Fight Chest Rig and wraps around your lower back. This strap can also be used as a sling if you wish to carry your Micro Fight in a cross-body configuration as a "Go Bag." The Micro Fight Back Strap has a maximum adjustment of 36 inches and a minimum adjustment of 8 inches. NOTE: The BACK STRAP is part of the Micro Fight Chest Rig System. This item does not include the chassis, shoulder straps, magazine inserts, or Mfg: Spiritus Systems