YONGNUO YN660 (Updated Version of YN560 IV) 2.4GHz Flash Speedlite Wireless Transceiver Integrated for Canon Nikon Pentax Olympus DSLR Cameras With WINGONEER Flash Diffuser GN66 GN66@ ISO100199mm Master controlSupports wireless master control function,realize six groups of light control Off camera Supports wireless slave function, fully supports the YN660YN560 IVYN560-TXRF605RF603IIRF602 wireless transmitter TriggerMultiple flexible trigger synchronous ways CustomSupports automatically save settings and custom settings Fn The parameters on the flash will automatically save when the flash turned off; the users can customize setting the flash function as needed.