Bought from an IIS member but never used as I haven't pursued deepsky photography with my SCT. These are no longer available from the manufacturer. Works as an off-axis guider with large pick-off prism and focal reducer. The focal reducer is an 80mm lens which can be used in two different positions or can be removed entirely. This allows it to work between f/4 and f/11. It yields crisp stars and no vignetting, unlike the Celestron and Meade f6.3 reducers. Can be used as a high quality visual reducer too, with the pick-off assembly removed - a great rich-field viewer that makes use of the whole light cone from the secondary.
It screws onto the 82mm back thread of 10 - 14" SCTs. Threaded to fit Celestrons. Manufacturer's info here:
http://www.lumicon.com/telescope-acc...F+14in+SCT&hn=
now $240 postage included