With my 2-inch Diagonal (William Optics) it won't allow to slew beyond 80 degrees elevation as it will hit base. Even when mounting telescope as far forward as possible. I can see how this may not be an issue for bases with longer arms like the Evolution, or smaller telescopes like the 6SE. Had to buy something else.
Bought for adapting my 2" Hotech centering T-Adapter. Works great, solid construction. Good secure locking wedge too, for those that don't use the Hotech centering adapters.
Fit perfectly with my Celestron and 2" attachments. Delivered ahead of schedule.
This adapter is very nicely made... but it will NOT thread onto older (late '70s) C8s. No currently-made adapter will.