The New filter Drawer for EOS Lens，26.5mm thickness is independently designed by ZWO and specifically made to match with ASI cooled cameras and EOS lens. You can freely use the 2”mounted filter with it.
It’s compatible with all ASI cooled cameras with 17.5mm back focus length (except ASI GT series).
It’s compatible with all ZWO 2” filters, including the duo-band filter, narrowband filter, IR-cut filter, etc.
With the ability of double strong magnetic adsorption, it is more convenient and much easier to install or pull out the filter.
The thread of the interface is M42*0.75. You can also use the M54M-M42F adapter to connect the filter drawer to a full-frame camera.