This set screw version of the diaelectrically coated 2" diagonal gives bright, crisp, contrasty images. there is a small (less than 1/8" by 1/8") wear mark where the bottom of my TV binovue, touched the mirror surface. I detect NO effect on optical performance. Having recently aquired a compression ring version, I don't need two.
For a more than 50% markdown, I think this would be a great buy for someone who wanted to step up to TeleVue quality. Your refractor will thank you for it.
thanks for looking