The Zev Technologies Glock Optimized Match Barrel Thread Protector is machined from 416R stainless steel. It is threaded 1/2x28 with a recessed muzzle that matches the angle of the target crown on the barrel. Machined with a unique profile to set it apart from the rest.Features: For 9mm Glock barrels Threaded 1/2x28 Machined from 416R stainless steelZEV Technologies began with a focus on competitive shooters, developing the first drop-in replacement triggers for Glock. From its early days, ZEV built its business with the philosophy that any part it made had to be the best product of its type available on the market. With ZEV products, feel confident that you are carrying the best product available for the competitive arena, the battlefield, or the local range.