The K9 11.5 offers a proprietary patrol length gas system that is smoother than carbine length, more reliable than mid-length. Features an optimized gas port to run reliably suppressed and/or unsuppressed. The K9 continuous taper is the most effective profile to dissipate heat from hard use. With weight shifted to the back of the barrel, modern attachments on the front of the rifle create a perfectly balanced and better handling rifle. Updated target crown carried over from the Purebred series with improved harmonics, fit and finish. We recommend a minimum handguard length of 10" with this barrel. NOTE: COMES WITH PATROL LENGTH GAS TUBE Barrel Length 11.5 Barrel Weight 25.47 oz Barrel Material 416R Barrel Caliber 5.56 Barrel Profile Continuous Twist 1/7 Barrel Thread 1/2 x 28 Barrel Gas Block Size 0.750 Gas System Length Patrol Barrel Crown Recessed Target Barrel Finish Nitride Barrel Extension Finish Nitride