Help urgently needed with adapter size

[eoliveira]

Hi,

Can someone tell me what female thread size is the EFW2 filterwheel hole, without the provided 2 inch adapter? I need to connect a TS off axis guider with a 2 inch female thread to the EFW2 female thread, but I am unsure of the size of the EFW2 connection.

Thank you in advance,

Eduardo.

[MikeM]

I believe it is M54 thread.