Presma .308 Steel Ejection Port Dust Cover Assembly AR-10 Steel Black. As pictured includes ejection port dust cover rod and spring Specifications for Presma .308 Steel Ejection Port Dust Cover Assembly: Manufacturer: Presma Color: Black Gun Model: AR-10 Caliber: .308 Winchester Package Contents: Presma .308 Steel Ejection Port Dust Cover Assembly What firearm models does the manufacturer say Presma .308 Steel Ejection Port Dust Cover Assembly is compatible with? The manufacturer says that Presma .308 Steel Ejection Port Dust Cover Assembly is compatible with AR-10Presma ARDC03: .308 Steel Ejection Port Dust Cover Assembly AR-10 Steel Black