Dark Storm Industries DS-15 Typhoon AR-15 5.56x45mm NATO 14.5inch Upper Receiver w/Pin and Weld Mid Length 1-7 Twist 1/2x28 Firestorm Compensator. 5 in Complete Upper is precision-built for reliability accuracy and long-term durability. Specifications for Dark Storm Industries DS-15 Typhoon AR-15 5.56x45mm NATO 14.5inch Upper Receiver: Manufacturer: Dark Storm Industries Caliber: 5.56x45mm NATO Barrel Length: 14.5 in Barrel Profile: SOCOM Gas System Length: Mid Length Barrel Twist Rate: 1-7 Threads per Inch: 1/2x28 Muzzle Device: Firestorm Compensator Fabric/Material: 4150 CMV Steel 7075-T6 Aluminum Handguard Length: 13 in Gun Rail: Picatinny Gun Make: AR Platform Gun Model: AR-15 Barrel Material: Steel Bolt Carrier Group Included: MIL-SPEC Charging Handle Included: MIL-SPEC Features of Dark Storm Industries DS-15 Typhoon AR-15 5.56x45mm NATO 14.5inch Upper Receiver Lifetime warranty Fully Transferable No Registration or Proof of Purchase Required Package Contents: Dark Storm Industries DS-15 Typhoon AR-15 5.56x45mm NATO 14.5inch Upper Receiver What firearm models does the manufacturer say Dark Storm Industries DS-15 Typhoon AR-15 5.56x45mm NATO 14.5inch Upper Receiver is compatible with? The manufacturer says that Dark Storm Industries DS-15 Typhoon AR-15 5.56x45mm NATO 14.5inch Upper Receiver is compatible with AR-15Dark Storm Industries DSI-UC5-TYP-14C7-PW5-BLK: DS-15 Typhoon AR-15 5.56x45mm NATO 14.5inch Upper Receiver w/Pin and Weld Mid Length 1-7 Twist 1/2x28 Firestorm Compensator Anodized Black