Nikon(G)-EOS fit for Nikon G Lens and Canon EOS Mount Camera ,your cannon 80D is E mount camera, so the adapter ring is fit for your camera 

The Olympus 100-400mm IS lens size is 72mm, please reconfirm the number mark as "ø" (diameter) symbol, if the number is 72, just need to order same 72mm size filter ,thanks. 

hello if your nikon camera is af mount, yes, you could make the sigma 70-200mm f/2.8 ex dg apo hsm large aperture macro zoom lens work with canon with this adoptor 

The K&F barely supported a Canon 400mm lens using the support arm of the lens. I found I had to really lock down to get the lens to hold position. I have moved on to another brand. 

FD-EOS fit for Canon FD mount lens and canon EF mount camera body. canon 60d is EF mount, so the adapter ring can work with your camera, but you need to check your lens mount. could you pls let us know your lens specific model? service(AT)kentfaith(DO NOT)com, Please note: It is not same between Canon FD mount and EF mount, this adapter ring is only for Canon FD mount lens, please contact us if you want to purchase for Canon EF mount lens.