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 

Si amigo si funciona con el sigma 16mm f1.4 porque el diámetro del anillo es de 67 igual. 

Unfortunately this is for adapting lenses to Olympus' modern digital Micro 4/3 cameras. It won't work with the Pen FT or similar half-frame film cameras, and you most likely won't find anyone making adapters for these. 

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. 

I don't think you need any. There is no glass.