This is a Blue Force Gear Magazine Pouch known as the Ten-Speed, model HW-TSP-M4-2-MC.
The Ten-Speed Double M4 Mag Pouch holds two M4 magazines and is the perfect blend of speed and security. Ten-Speed(R) pouches use military grade elastic combined with ULTRAcomp to create a multiuse pouch that is weighs almost nothing and lays flat when not in use. The Double M4 Mag Pouch holds two M4 magazines (polymer or metal)" medical supplies" bandages" flash bangs" or other similar sized items.
Features:
Fits two M4 magazine (polymer or metal
Flash bangs
Bandages
Small radios
3x4 Molle field required