YONGNUO YN560 IV Wireless Flash Speedlite Master + Slave Flash + Built-in Trigger System for Canon Nikon Pentax Olympus Fujifilm Panasonic Digital Cameras YN560 IV=YN560III+YN560-TX, Supports Wireless Master Function. Supports Wireless Slave Function, fully supports YN560-TX, RF-603 II RF-602 Wireless Transmitter. Supports Multiple Trigger Synchronous Mode. Enure the battery is fully changed. Supports setting save automatically, custom settings ( fn ). Verify the Flash light setting Supports ultra-fast charging recycle system, External power supply. Check the remote control settings before use