Slave Flash, Manual, TTL
From Amazon
Hähnel - MODUS 600RT MK II - Speedlight - for Fujifilm - Wireless connectivity - TTL, Manual & Multi Modes - Quick-lock hot shoe - Built-in 2.4GHz wireless receiver & transmitter
Clifton Cameras
Hahnel Modus 600RT MK II Speedlight - Fujifilm
OnBuy
Modus 600 RT mkII for Fuji