The insert is only compatible with the Micro Fight MK3 and MK4 Chassis and not with MK1 or MK2 Chassis, nor plate carrier kangaroo pouches.
It is designed for quiet and easy access to magazines using elastic for retention, fitting both PMAGS and USGI magazines.
The product is available in Jet Black, with dimensions for 5.56 x .45 magazines at 9" x 4", and is a required component for the Micro Fight Chest Rig System.