Enhances Trigger Pull by holding hammer tightly in frame. Left side of hammer pin measure OD 0.177" and right side measure OD 0.147". Will require to ream the hammer hole and frame's hammer holes. Due to inaccuracy in factory parts and frames, it's necessary to go to the biggest diameter to achieve a perfect hammer to frame fit. Hammer pin fits Gold Team/Custom, Limited, Stock II , Hunter, Gold Match. The other benefit of this pin is that it won't wear like the factory pin does, causing the hammer to wobble and give inaccurate trigger pulls. Works very well with EGW aftermarket single action hammers.