AF-assist illumination
2nd curtain sync activation (currently only in M mode)
Firmware update via USB port
Full compatibility with Canon 600EX-RT, Canon ST-E3-RT, Yongnuo YN-600EX-RT
Supported modes: E-TTL II / Y-TTL, M, Multi, GR
Control of five groups (A, B, C, D, E)
Master and slave modes
15 fixed channels, 1 auto channel
High-speed sync (FP flash, HSS)
Manual flash power control 1/1–1/128
E-TTL II power ratio control, 1/3-step increments
Flash exposure compensation (FEC)
Flash exposure lock (FEL)
Flash exposure bracketing (FEB)
Modeling flash
TEST function
Linked Shot (requires a special cable; the camera must support this function)
Remote shutter release




