YN-E3-RT Yongnuo Flash Speedlite Transmitter Compatible with 600EX-RT ( Item#: D1094 )

Features:
It includes all the features of ST-E3-RT, as well as extra features including 
USB port for firmware updates.
AF focus assist light. 
Full GR Group Mode functionality has also now been added for pre 2012 model cameras. 
Slave flash charge status does not stop other flashes from firing.

YN-E3-RT features:
Two-way 2.4G radio communication, fully compatible with ST-E3-RT / 600EX-RT.
Control up to 5 groups (15 units) of Speedlites.
15 physical channels, 1 auto channel, up to 10,000 customizable photographer ID.
Transmission range: 100M.
Multi YN-E3-RT can share slave flashes.
Display group/charge status of slave flashes.
Firmware can be upgraded via USB (You need to buy extra USB Cable).
High resolution Dot-Matrix LCD, Backlight for LCD/keys.
Fast lock mechanism.
Built-in AF assist beam emitter, buzzer.
Remote shutter release, Linked Shot (Need extra shutter cable for cameras released before 2012).
Flash mode: ETTL / M / Multi / GR 4 flash modes.
A/B/C/D/E 5 groups.
Supports 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.
9 custom functions.
Settings saved automatically.
Dust and water resistance equivalent to EOS-1D series cameras.

Specifications:
Type: On-camera Speedlite transmitter
Compatible cameras: EOS type-A camera compatible with E-TTL II/E-TTL autoflash
Exposure control system: E-TTLII/E-TTL autoflash, manual flash, stroboscopic flash, auto external flash metering (Only when teh flash mode is set to <Gr>)
Modulation system: Primary modulation: OQPSK, secondary modulation: DS-SS
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. 100 m
Flash ratio control: 1:8-1:1-8:1, 1/2-stop increments Flash exposure
compensation: ±3 stops in 1/3- increments
FEB: ±3 stops in 1/3- increments (when used with flash exposure compensation)
FE lock: Press the camera's ( M-Fn), ( FEL), or ( *) button
High-speed sync: Provided
Manual flash: 1/1-1/128 power(1/3-stop increments)
Stroboscopic flash: Provided(1-500 Hz)
Linked shooting: Provided
Custom functions: 9
AF assist beam emitter：Provided
Firmware update：Provided
Power source: 2 * AA/LR6 alkaline batteries Ni-MH batteries （Not included)
Wireless flash shooting Approx. time: 10 continuous hours (When using AA / LR6 alkaline batteries)
Power saving: Power off after 5min. of idle operation
Item dimension: Approx. 8.8 * 6.8 * 5.8cm / 3.5 * 2.7 * 2.3in
Item weight: 110g / 3.77oz
Package dimension: 11 * 9 * 7.8cm / 4.3 * 3.5 * 3.1in
Package weight: 230g / 8oz


Package List:
1 * Yongnuo Speedlite Transmitter YN-E3-RT
2 * Shutter Release Cable For Camera (C1 / C2)
1 * Manual (English & Chinese)
1 * Protect Bag