This finder base is used the larger FBD shoe. Check the FBD drawing above and make sure the slots on the shoe have the correct spacing for your SCT. It generally fits 8" and larger SCT's (Schmidt Cassegrain Telescopes).
Note: We do not supply these with attachment screws. Many SCT mirror cells use threaded holes that are open and if too long a screw is used it can strike and damage the mirror. So, use the appropriate length screw that will not extend into the mirror cell deeper than the screws you remove from these threaded holes.