Some late model Celestron 8" SCTs don't have the required mounting
holes for attaching rails and mounting plates.

For our counterweight and piggyback rails to fit, there must be accessory
mounting holes on top and bottom of the end cells of the scope.

On the rear cell center line there should be two holes side by side,
spaced 1-3/4" apart. These are threaded 8-32 holes.

On the front cell center line there should be one hole spaced 12-1/4"
from the rear holes. This hole is threaded 8-32 or 10-24.

The three accessory mounting holes have dome-head or round-head
screws in them that can be removed to mount accessories.

Don't remove any screws from your Celestron 8" OTA until you are
certain that the rail holes line up with the screws!

Never remove any flat-head countersunk screws from the OTA!!