With twice the capacity of the single mag case, Blackhawk's double mag case is curved to the waistline for slimmer profile, and an adjustable belt-clip hook accommodates belts of different widths. It has a built-in tension spring to securely hold magazines of various sizes. This single stack model has compartments for two single stack magazines and a matte black finish. Holds single stack magazines for 9mm / 40 / 45 Cal / 357Sig and others in that class. One of the most secure magazine cases on the market. Excellent for duty when you could be running or involved in a use of force and for Tactical Team Members.