ABC RIFLE COMPANY AR-15 .223 Remington/5.56x45mm NATO Micro Pistol 5in Barrel Custom 5in Top Cut Custom M-LOK Handguard Complete Upper Receiver w/BCG. 56 NATO barrel with a 5in M-LOK handguard featuring an integrated handstop for added control. A low-profile steel gas block 5 3/16in stainless micro gas tube and 7075 aluminum flash can keep recoil manageable and function smooth. Outfitted with an MPI-tested full-auto rated nitride BCG milspec ejection port cover forward assist and a battle latch charging handle for fast reliable operation. Specifications for ABC RIFLE COMPANY AR-15 .223 Remington/5.56x45mm NATO Micro Pistol 5in Barrel Custom 5in Top Cut Custom M-LOK Handguard Complete Upper Receiver w/BCG And Charging Handle: Manufacturer: ABC RIFLE COMPANY Caliber: 5.56mm .223 Remington 5.56x45mm NATO Barrel Length: 5 in Barrel Twist Rate: 1-5 Threads per Inch: 1/2x28 Muzzle Device: Muzzle Diverter Flash Can Handguard Length: 5 in Gun Rail: M-LOK Gun Type: Rifle Gun Make: AR Platform Gun Model: AR-15 Gas Block Journal Size-Length: .750 in Bolt Carrier Group Included: MIL-SPEC Charging Handle Included: MIL-SPEC Package Contents: ABC RIFLE COMPANY AR-15 .223 Remington/5.56x45mm NATO Micro Pistol 5in Barrel Custom 5in Top Cut Custom M-LOK Handguard Complete Upper Receiver w/BCG And Charging Handle What firearm models does the manufacturer say ABC RIFLE COMPANY AR-15 .223 Remington/5.56x45mm NATO Micro Pistol 5in Barrel Custom 5in Top Cut Custom M-LOK Handguard Complete Upper Receiver w/BCG And Charging Handle is compatible with? The manufacturer suggests that ABC RIFLE COMPANY AR-15 .223 Remington/5.56x45mm NATO Micro Pistol 5in Barrel Custom 5in Top Cut Custom M-LOK Handguard Complete Upper Receiver w/BCG And Charging Handle is compatible with AR-15ABC RIFLE COMPANY UA15B-BR5-TCML5-BLK: AR-15 .223 Remington/5.56x45mm NATO Micro Pistol 5in Barrel Custom 5in Top Cut Custom M-LOK Handguard Complete Upper Receiver w/BCG And Charging Handle Black