Angstadt Arms Complete Upper Assembly AR-15 5.5 in Handguard 6 in Barrel A2 Flash Hider Picatinny/M-LOK 1/2x28 Black AAUDP0906U. Ready to run with any 9MM AR-15 dedicated lower receiver. Specifications for Angstadt Arms AR-15 Complete 9mm Upper Receiver with Flash Hider Assembly: Manufacturer: Angstadt Arms Caliber: 9mm Luger Overall Length: 6 in Barrel Length: 6 in Barrel Twist Rate: 1-10 Threads per Inch: 1/2x28 Handguard Type: Free-Float Color: Black Gun Model: AR-15 Condition: New Fabric/Material: 7075-T6 Aluminum Handguard Length: 5.5 in Gun Rail: Picatinny Gun Type: Rifle Gun Make: AR Platform Included Accessories: Standard Weight: 2.6 lb Magazine Included: No Quantity: 1 Package Contents: Angstadt Arms AR-15 Complete 9mm Upper Receiver with Flash Hider Assembly What firearm models does the manufacturer say Angstadt Arms AR-15 Complete 9mm Upper Receiver with Flash Hider Assembly is compatible with? The manufacturer suggests that Angstadt Arms AR-15 Complete 9mm Upper Receiver with Flash Hider Assembly is compatible with AR-15Angstadt Arms AAUDP0906U: Complete Upper Assembly AR-15 5.5 in Handguard 6 in Barrel A2 Flash Hider Picatinny/M-LOK 1/2x28 Black