$108 shipped. The kit (this is not the Everbrite version) sells for $300 on several web sites. Please read entire ad for details.
The Televue web site says:
"This kit contains everything needed to triple the true field area of a Schmidt-Cassegrain. Just thread the SCT adapter onto the back of your Celestron or Meade visual back to use 2" format accessories. Kit includes: SCT Adapter, 2" Star diagonal, 2" to 1 1/4" adapter."
But it turns out it that it is for 7" to 16" SCTs and I have a 5" SCT.
I purchased the Televue SCT Adapter separately from the Televue 2" star diagonal and the Televue 2" to 1 1/4" adapter; they are all Televue components and all work together perfectly.
The visual back uses set screws and so does the diagonal and the 2" to 1 1/4" adapter. No endcaps, one original box for the 2" to 1 1/2" adapter.
The finish on the visual back has some scratches. The mirror is dusty, but more importantly, has very fine scratches across the surface. I have used this diagonal and did not observe any noticable problems myself, obtaining sharp, contrasty views with the appropriate eyepieces. Nevertheless a serious discount.
I have used this for a while even though it vignettes 2" eps in the 5" SCT, because the views appeared brighter to me than using the stock Celestron 1.25" diagonal. If it did not vignette 2" eps I would certainly keep using it.