I have had one for years that came side mounted on my first P-17, it has been sitting in my closet and I just finally figured out the worn out name with a strong magnifier. This thing is really old and has really outdated windage and elevation settings, it is about 2x with a micro-thin crosshair and a center dot. 7/8ths straight tube with about 1&1/4 bell at the eyepeice only. It also say's US Pat. Pend and a '4' in the center of the logo.