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.
Part of the Optolong SHO-3nm filter kit, which includes SII 3nm, H-Alpha 3nm, and OIII 3nm narrowband filters, generally working with astronomical monochrome cooling CCD and modified DSLR imaging in each single-channel. Corresponding with RGB channel (HA, OIII, SII), photographers can process Hubble images by astronomical post processing software.