Luth-AR Mark 12 18 in 5.56 Upper Kit Less Lower Receiver Black

Luth-AR 18 in Mark 12 kit minus Lower Receiver w/fixed stock Black Rifle. 56mm Overall Length: 28 in Barrel Length: 18 in Barrel Profile: Heavy Barrel Twist Rate: 1-9 Firearms Threads Per Inch: 1/2x28 Handguard Type: Free-Float Muzzle Device: A2 Flash Hider Finish: Anodized Color: Black Gun Model: AR-15 Fabric/Material: Aluminum Gas Block Journal Size-Diameter: .750 in Handguard Length: 15 in Gun Rail: M-LOK Magazine Included: No Country of Origin: USA Package Contents: Luth-AR 18 in Mark 12 kit minus Lower Receiver w/fixed stock Fully assembled 18 in MARK 12 5.56 mm Upper with 15 in Keymod Palm Handguard MBA-1 Buttstock Assembly Complete Lower Parts Kit What firearm models does the manufacturer say Luth-AR 18 in Mark 12 kit minus Lower Receiver w/fixed stock is compatible with? The manufacturer suggests that Luth-AR 18 in Mark 12 kit minus Lower Receiver w/fixed stock is compatible with AR-15Luth-AR RKM12-18-1M: 18 in Mark 12 kit minus Lower Receiver w/fixed stock Black Rifle