【Two-way 2.4G radio communication, fully compatible with the Canon 600EX-RT flash speedlite and the ST-E3-RT transmitter】Two-way 2.4G radio communication, fully compatible with ST-E3-RT, 600EX-RT, YN E3-RT, YN968EX-RT, YN600EX-RT(II), YN686EX-RT, YNE3-RX. | 【Compatible Canon Cameras】 70D, 60D, 50D, 40D, 30D, 100D, 80D, 5DIV, 6DII, 5DIII, 5DII, 5D, 6D, 7D, 7DII, 1D, Rebel T5i, Rebel T4i, Rebel T3i, Rebel T2i, T1i, Rebel XSi, Xti, Rebel XT, Rebel XS, EOS R; Canon speedlite: 600EX (II)-RT 430EX III-RT; YONGNUO speedlite: YN600EX-RT (II), YN968EX-RT, YN686EX-RT, YN680EX-RT. | 【4 Flash Modes, 5 groups】 ETTL, M, Multi and GR flash modes. Up to 5 groups (A/B/C/D/E) and 15 units. Supports 1st curtain, 2nd curtain(Only in M mode), high speed sync. | 【Multi YN-E3-RT II can share slave flashes】15 Physical Channels, 1 Auto Channel, Up to 10,000 customizable photographer ID. Transmission Range: 100M. Multi YN-E3-RT II can share slave flashes, display group/charge status of slave flashes. | 【Remote shutter release, Linked Shot 】New designed select dial and display interface for easier operation. Supports remote control to set the focal length (ZOOM) of the slave flash (Compatible with YONGNUO compatible flashes only). Firmware can be upgraded via USB(Micro-USB) | 【Additional Function】High resolution Dot-Matrix LCD, Backlight for LCD/keys; Supports ETTL Ratio, Flash Exposure Compensation, Flash Exposure Lock, Flash Exposure Bracket, Modeling Flash, Built-in AF assist beam emitter, buzzer, 9 Custom Functions.