Zaffiri Precision match grade barrels for GlockA(R) G17 Gen 1-4. High quality performance you demand with an easy drop-in barrel upgrade. THREADED BARREL Threaded - 1/2 x 28 muzzle Thread protector is included Length: 4.99" Note: Threaded pistol barrels are not legal in all areas. It is your responsibility to check your local laws before ordering a threaded barrel. NON-THREADED BARREL Flush and Crown - flush with end of slide / inward "crown" shape Length: 4.34" SPECS Compatible for GlockA(R) 17 Gen 1-4 Twist: 1/10 Quality: 416R Stainless Steel Stress relieved and heat tr Mfg: Zaffiri