Canon EF Adapters with glass for Infinity Focus - to mount on Canon EOS body, has a 2 element multicoated glass element in the adapter to allow far focusing due to the flange to sensor distance being further than required. 

Canon FD to Canon EOS - Mounts older film SLR Canon FD mount manual lenses to EOS body. Consists of a 2-element multicoated glass in the adapter to allow focusing to infinity. Image quality remains good. Better when slightly stopped down.