ZEV Technologies Optimized Match Barrels have been redesigned for improved performance and Gen5 compatibility. Enhanced features include a recessed target crown, a new match chamber, and a stylized barrel hood with caliber and model engravings and a loaded chamber indicator. ZEV's proprietary broach cut 1 in 14" left hand twist rifling was developed to create the most accurate Glock aftermarket barrel available, and testing confirms a significant increase in accuracy over factory barrels. Mfg: Zev Technologies