Chiappa Firearms M4-22 Gen II Pro Conversion Kit Upper Receiver 22LR 16" Heavy Barrel 11.8" Forend 8 Position Picatinny Rail 2 Magazines Black 10Rd. 22LR rifle perfect for plinking of training. The forend is a 11.8in long Quad Picatinny with a 16in steel barrel. Specifications for Chiappa Firearms M4-22 Gen II Pro .22 Long Rifle 16in Picatinny Upper Receiver: Manufacturer: Chiappa Firearms Caliber: .22 Long Rifle Barrel Length: 16 in Barrel Profile: Heavy Contour Barrel Twist Rate: 1-16 Firearms Threads Per Inch: 1/2x28 Finish: Matte Color: Black Gun Model: AR-15 Fabric/Material: Polymer Handguard Length: 11.8 in Gun Rail: Quad Picatinny Gun Type: Rifle Gun Make: AR Platform Weight: 6 lb Magazine Included: Yes Package Contents: Chiappa Firearms M4-22 Gen II Pro .22 Long Rifle 16in Picatinny Upper Receiver What firearm models does the manufacturer say Chiappa Firearms M4-22 Gen II Pro .22 Long Rifle 16in Picatinny Upper Receiver is compatible with? The manufacturer suggests that Chiappa Firearms M4-22 Gen II Pro .22 Long Rifle 16in Picatinny Upper Receiver is compatible with AR-15Chiappa Firearms M4-22 Gen II Pro Conversion Kit Upper Receiver 22LR 16" Heavy Barrel 11.8" Forend 8 Position Picatinny Rail 2 Magazines Black 10Rd 500.096