For Sale Horseman 2X LF Tele-Convertor

This is a Horseman 2X LF Tele-Convertor that's in excellent condition. Glass has no scratches that I can see. (Certainly nothing obvious.) When installed, it doubles the focal length. I believe that, in particular, it was designed to convert a 150mm lens into a 300mm lens. The build quality of this tele-convertor is excellent.

Logistically, one replaces the retaining ring of a 150mm lens with the adapter shown at the upper right of the 1st image. When attached in this manner, the lens looks like that in the upper left of the 2nd image. In that configuration, the lens operates at its normal, 150mm focal length.

To tele-convert the lens, the device on the upper right of the 2nd image is attached to that of the upper left, and together, they operate as a 300mm lens. (See 3rd photo.) The effective aperture will be double that selected on the lens. (So, if an aperture of f16 is selected on the lens, the effective aperture of the tele-converted 300mm lens will be f32.) The image of the 300mm converted lens will be sharp, though not as sharp as the non-converted, 150mm lens.

Asking $135 plus shipping. I ship insured with signature required by USPS Priority Mail.