Farpoint Dew Shield - Celestron 8 Inch SCT and 8" RASA
It's good. Still have to notch it for the dovetail on the OTA, but that's trivial. The nice thing about it is that I ordered the wrong one by mistake, and Farpoint was just cool about it. Sent it back, ordered this one, and got a refund with no hassle. I paid return shipping, so I don't recommend ordering the wrong item, but if you do, Farpoint is nice about it.
I bought this for my orion XT8 Plus Newtonian. After measuring the tube OD, I knew it would fit the scope. Works as a light shield as well as a dew preventer for the diagonal.
The Farpoint Dew Shield for the 8" SCT is an excellent performer. I'd not purchase another brand.