At this time, the only official UNISTELLAR filter available is the Smart Solar Filter : A New Space Experience: the UNISTELLAR Smart Solar Filter.
It is possible to install 3rd party filter on the EXPERT Range (EQUINOX and EVSCCOPE). However, please keep in mind that using filters troubles the collimation. Adding a filter to your camera is at your own risk. In case of damage, or in case you used a filter, and we discover your fingerprints on the camera upon inspection, your unit will not be covered by our warranty.
It is not possible to install 3rd party filter on the ODYSSEY and ODYSSEY PRO.
It is also worth noting that not all third-party filters are tested with our image processing algorithms, and you may experience unexpected behavior when observing with third-party filters.