Designed around the 1911 frame and competition race guns, the Serendipity started the heads-up revolution in shooting sports. In 1993 it was the first sight ever used in competition to incorporate a heads-up display or "tubeless" design. Since then the Serendipity has proven its performance and reliability with multiple National and World Championships, and continues to be the DOMINATE sight in competition today. The Serendipity is available in ten different models. The difference in each model is the intensity switch and the width of the mounting pads, which are machined to fit the width of the selected frame.The Serendipity mounts directly to the frame by drilling and tapping six holes, three on each side. Although the Serendipity was designed for the 1911 frame, the dimensions of the mount allow it to be installed on other "select" frames as well. Check models for a complete list of approved frames.