Baader Camera adaptor Protective CANON DSLR T ring with built-in H-alpha 7nm narrowband filter
Baader Wide-T-Ring Canon EOS with D52i to T-2 and S52 — Alpine Astronomical LLC
William Optics 48mm Wide T-Ring for Canon SLR/DSLR EOS Cameras - Black # TM-CN-EOS-M48
Canon DSLR Standard T-Ring - 42 mm - Stellarvue
Baader Wide-T-Ring Canon EOS with D52i to T-2 and S52
Amazon.com: SVBONY T2 T Ring Adapter and T Adapter, 1.25 inches Metal Telescope Camera Adapter for Canon EOS Standard EF Lenses and Telescope Camera Astrophotography Accessories : Electronics
Canon Camera 1.25" T-adapter and T-Ring adaptor kit
Low Profile 48mm T-Ring for Canon EOS-R
Baader Protective T-Ring w/ 2" Nosepiece for Canon EOS without any Filters (BPEOS) - Astro-Physics