This is a piggyback camera rail for Meade 8" SCTs. It is very nice for mounting heavy equipment, and is much more solid that any other that I have used. I'm moving up to a 10" scope, but I'm sorry to see this one go.
You can find more information on Losmandy's site, listed as part number "PB C8/M8".
I'm asking $60 shipped in the continental USA. I accept paypal and money orders. Please feel free to contact me with any questions.