Agency Arms® Mid Line Barrels are for those who desire functionality as well as a unique appearance. While each of our lines maintain the same core accuracy and reliability, Our Mid Line focuses on additional machining enhancements and appearance while only a having modest price increase over the Standard Line models. Specifications Twist: 1/10 Quality: 416R Stainless Steel Rifling: Pulled broached/ Saami Spec 9mm Rifling Fit: Compatible with Glock® 17 Gen 5 Caliber information machined on the rear of the lockup. Identified as "917" Threading (Optional): 1/2 x 28 Thread protector (Price included with threading): Yes, In matching finish! Finish Options: Stainless Steel, Black Nitride, Titanium Nitride (Gold) Barrel Length: Sits Flush with Slide (non-threaded only) Deep Crown (non-threaded only) Large Agency “A” machined on the Top of the lockup. Large “AGENCY” machined on the Port Side of the lockup. (7) Gear Flutes machined around the circumference of the barrel.