KCI USA AR-15 Drum Rifle Magazine 5.56x45mm NATO 100 Round Black 1 Pack Polymer 100RD. 56x45mm or 223 Remington. The drum feeds alternately from the left and right sides using two independent follower belts to maintain a balanced center of gravity while firing. Features steel-reinforced feed lips for added durability and reliable feeding. Includes the KCI USA 100 Round Drum Operators Manual Carrying Pouch Graphite Lubricant and Loader. Specifications for KCI USA AR-15 5.56x45mm NATO 100 Round Drum Rifle Magazine: Manufacturer: KCI USA Color: Black Fabric/Material: Polymer Magazine Capacity: 100 Round Caliber: 5.56x45mm NATO Gun Make: AR Platform Package Contents: KCI USA AR-15 5.56x45mm NATO 100 Round Drum Rifle Magazine KCI USA KCIMZ001-100RD: AR-15 Drum Rifle Magazine 5.56x45mm NATO 100 Round Black 1 Pack Polymer