The ZWO spare 2″ filter holder is compatible with the new 2023 version (V2) of the ZWO M42 & M54 filter drawers, as well as the standard Nikon and Canon filter drawers.
Note: This is NOT compatible with the previous version of the ZWO filter drawers.
The holder is suitable for use with all ZWO 2″ mounted filters and most 2″ filters on the market which conform to the following measurements: