Arc Division Threaded Barrel Glock 17 9mm Drop In 1-10 Twist 1/2x28 TPI 4150 Steel Bronze. Specifications for Arc Division 9mm Threaded Barrel: Manufacturer: Arc Division Threads per Inch: 1/2x28 Barrel Twist Rate: 1-10 Caliber: 9mm Luger Gun Make: Glock Condition: New Package Contents: Arc Division 9mm Threaded Barrel What firearm models does the manufacturer say Arc Division 9mm Threaded Barrel is compatible with? The manufacturer suggests that Arc Division 9mm Threaded Barrel is compatible with Glock 19 Glock 17Arc Division 55388: Threaded Barrel Glock 17 9mm Drop In 1-10 Twist 1/2x28 TPI 4150 Steel Bronze