WARNING: This insert is ONLY compatible with the Micro Fight MK3 and MK4 Chassis. It is not compatible with the MK2 or MK1 Chassis, nor plate carrier kangaroo pouches. The 5.56 Rifle Single Insert is a custom insert that allows you to plus-up magazines one by one. It can fit into either pocket on the Micro Fight Chassis MK 3, as well as the FRONT POCKET only on the MK2. This product is not compatible with the MK1 series. Using elastic is very quiet when removing or adding magazines, giving you quick and easy access to your magazines while providing excellent retention. This product is also compatible with the Unity Tactical CLUTCH belt. &nb Mfg: Spiritus Systems