The SBIG FR-237 focal reducer lens threads directly into the 1.25" nosepiece of the STV increasing the field of view.
The same lens when used with the e-finder extension tube turns the FR-237 lens into a compact f/4 telescope with a 100mm focal length.
Outfitted with the Borg 7315 miniature helical focuser and 7316 1.25" nosepiece, the e-finder can be easily used for autoguiding without an additional guidescope.
New, this setup would cost $342 prior to shipping. You can have it all for only $285 and I will pay for shipping and insurance within the CONUS.
Although I prefer PayPal, I will accept USPS money orders.