This Nylon MDS hammer with brass insert will make your gun cock smooth as butter! The external layer is self lubricating Nylon, so since there’s no more metal on metal it will reduce over dwell of valve and lower your ES in most cases. It is also quieter, as nylon on steel makes very little noise unlike steel on steel. This product fit’s 177/22/25 Cal Benjamin Marauder Rifle’s. This item weighs 1.77oz, and is pre-drilled for the factory striker. Simply unscrew the striker from your stock hammer and screw into this hammer, and install.