This vixen made in Japan illuminated guiding adapter is the very rare .965" model. It can be used with any eyepiece of .965" size and turns any telescope into a guiding scope. It works by projecting a red reticle image of adjustable intensity on the field of view of the eyepiece. The image of the star chosen to guide on remains visible with the reticle on. The position of the reticle can be moved over the field of view so as to reach a variety of guide stars within the field of view. It includes a removable 3X Barlow. The eyepiece can be rotated to adjust the focus of the reticle. Uses two common small batteries not included. This is the very rare .965" model of which very few were imported. Very lightly used and a great addition to anyones collection of vintage vixen products.