Elite Force HK UMP 120rd Mid-Cap Competition Series Magazine Black. Our HK UMP mid-cap magazines are made from durable lightweight polymer material that won t weigh you down so that you can stock up (on more mags). It never hurts to have a spare Specifications for Elite Force HK UMP 120rd Mid-Cap Competition Series Magazine: Manufacturer: Elite Force Color: Black Fabric/Material: Plastic Magazine Capacity: 110 Round Projectile Caliber: .243 Caliber Package Contents: Elite Force HK UMP 120rd Mid-Cap Competition Series Magazine Elite Force 2278058: HK UMP 120rd Mid-Cap Competition Series MagazineBlack