Yongnuo YN-E3-RT II TTL Radio Trigger Speedlite Transmitter as ST-E3-RT Compatible with Canon 600EX-RT and YONGNUO YN600EX-RT II YN968EX-RT Yongnuo YN-E3-RT II Speedlight Transmitter is compatible with the Canon 600EX-RT flash unit and ST-E3-RT transmitter, it provides practically all the features of the original Canon ST-E3-RT, plus a number of important extra features, these include a built in AF assist light, 2nd Curtain Sync (Only in M mode), USB port for firmware upgrade, and added range to 100 Meters. Features: Two-way 2.4G radio communication, fully compatible with ST-E3-RT/600EX-RT15 Physical Channels, 1 Auto Channel, Up to 10,000 customizable photographer IDTransmission Range: 100MMulti YN-E3-RT II can share slave flashesFirmware can be upgraded via USBHigh resolution Dot-Matrix LCD, Back-light for LCD/keys,Built-in AF Lamp, buzzerFlash Mode: ETTL/M/Multi/GR (GR Mode only works with cameras released since 2012)A/B/C/D/E Five groupsSupports 1st Curtain, 2nd Curtain (Only in M mode), High speed Sync,Supports ETTL Ratio, Flash Exposure Compensation, Flash Exposure Lock, Flash Exposure Bracket, Modeling Flash Suit for: ALL Canon DSLR Camera with E-TTL II / E-TTL autoflashCanon 600EX-RTCanon ST-E3-RTYongnuo YN600EX-RT II, YN968EX-RT Features Type: On-Camera Speedlite Transmitter Exposure Control Syestem: E-TTL II/E-TTL Autoflash, Manual Flash, Stoboscopic Flash, Gr Flash Frequency: 2405-2475 MHZ Channel: Auto, Ch. 1-15 Wireless Radio ID: 0000-9999 Slave Unit Control: Up to 5 Groups(A/B/C/D/E), Up to 15 Units Transmission Distance: Approx. 100m Flash Ratio Control: 1:8-1:1-8:1, 1/2-Stop Increments Flash Exposure FEB: ±3 Stops in 1/3-Increments (When used with flash exposure compensation) Compensation: ±3 stops in 1/3- increments Manual Flash: 1/1-1/128 Power (1/3-stop increments) Flash Exposure Confirmation: Flash Exposure Confirmation Lamp Lights Power Saving: Power off After 5 min, of idle Operation Power Source: 2 AA/LR6 Alkaline Batteries Ni-MH Batteries (Not Included) Wireless Flash Shooting: Approx. Time: 10 Continuous Hours Stroboscopic Flash: Provided (1-500Hz) Modeling flash: Fired with camera‘s depth-offield preview button Custom Functions: 9 Dimensions: Approx. 67.7 (W) x 66.7 (H) x 81.3 (D) mm Weight: Approx. 110g Hot shoe compatible with Canon Camera Metal Hot shoe Remote shutter release There are two shutter release cables to work with Canon DSLR Cameras Package Included: 1 x YN-E3-RT II 2 x Shutter release cable for Canon camera 1 x Manual in English and Chinese 1 x Protect bag 1 x Original box