300mm F6.3 Catadioptric Compact Telephoto for Mirrorless Cameras – Samyang US
Catadioptric system - Wikipedia
A bit of history about Canon and catadioptric (mirror) lenses
Buy 900mm F/8 Mirror Lens for Canon 1100D 550D 600D 650D 700D 1000D Digital Cameras+T2 Mount Online at Low Price in India | Non-brand Camera Reviews & Ratings - Amazon.in
Tokina Annonuces the Releases of 3 New Catadioptric Lenses - Exibart Street
SZX 500mm f/8 Reflex for Canon EF Mount – Tokina Lens USA
Keppler's Vault 61: Mirror Lenses - mike eckman dot com
Rokinon Reflex 300mm f/6.3 ED UMC CS Lens for Can 300M-M-BK B&H