Luth-AR AR-15 .223/5.56mm Slick Side A1 Upper Receiver Part Hard Coat Anodized Black. Correct early-style carry handle contours with A1-pattern rear sight housing. The assembled version of the Slick Side A1 includes the A1 Rear Sight and Ejection Port Cover Door Assemblies installed. The Slick Side A1 Upper eliminates the shell deflector and forward assist. Charging handle components sold separately. All points where other parts attach are finished current mil-spec dimensions. Current production AR-15 components will fit perfectly. Note that the AR-15 / M16 Slick-side Upper Receiver is period-accurate therefore it DOES NOT have M4-type feed ramps found on most current-production AR-15 flattop upper receivers Specifications for Luth-AR AR-15 .223/5.56mm Slick Side A1 Upper Receiver Part: Manufacturer: Luth-AR Color: Black Finish: Hard Coat Anodized Fabric/Material: 7075-T6 Aluminum Caliber: 5.56mm .223 Remington Gun Make: AR Platform Gun Model: AR-15 Weight: 7 oz Muzzle Device: No Package Contents: Luth-AR AR-15 .223/5.56mm Slick Side A1 Upper Receiver Part What firearm models does the manufacturer say Luth-AR AR-15 .223/5.56mm Slick Side A1 Upper Receiver Part is compatible with? The manufacturer says that Luth-AR AR-15 .223/5.56mm Slick Side A1 Upper Receiver Part is compatible with AR-15Luth-AR UR-01-E3-SA: AR-15 .223/5.56mm Slick Side A1 Upper Receiver Part Hard Coat Anodized Black