Shanny SN-E3-RTs Transmitter Flash Trigger for Canon 600EX-RT Yongnuo YN600EX-RT SN600C-RT Flash Speedlite As ST-E3-RT YN-E3-RT Compatible camera: Compatible with E-TTL II/E-TTL Auto Flash A type EOS Camera Automatically With Gr/ E-TTL/ M/ Multi 4 kinds of flash modes 2.4G wireless transmission, up to 30m remote control distance Slave Unit Control: Up to 5 Groups(A/B/C/D/E), up to 15 salve flashes Support E-TTL ratio/ flash exposure compensation/ flash exposure lock/ bracket exposure