My research says that it's compatible with most Canon DSLRs with problems reported only with Canon 5D Mkiv and Canon 80D.
YONGNUO YN14EX Macro Ring Flash for Canon DSLR Cameras
Yongnuo YN14EX Macro Ring Lite DEFECTIVE/PARTS ONLY
Yongnuo YN14EX Macro Ring Lite Flash LED Light with Adapter Rings for Canon
Yongnuo Digital Macro Ring Lite YN14EX for Canon
YONGNUO YN14EX II Macro Ring Flash for Canon DSLR Cameras, with Adapter Rings and Color Temperature Filters, Hot Shoe Mount, Support M, TTL Flash
Yongnuo YN14EX II LED Macro Ring Flash for Canon
