Features: GN 60m (ISO 100 / 200mm) HSS to 1/8000th Flash Mode- ETTL /M / Multi 1st Curtain Sync / 2nd Curtain Sync FEC / FEB-1/3rd Increments (3 stops) Manual Flash-1/128-1/1 output control (1/3rd increments) 20-200mm Auto and Manual Flash Zoom Built-in Radio Slave Modes-YN-622C & RF-603 / YN-560, 2.4GHz RF Systems. Full Power Recycle-From 3 Seconds Supports Multiple Flash Groups Supports Multiple Channels Custom Functions Auto Save Settings Sound Prompt Heat Protection Large Dot Matrix LCD Screen Canon Like Interface AF Assist Light 360 Degree Swivel and Tilt Head Fast Clamping Metal Foot External HV Battery Port USB Port for Firmware Updates PC Sync Port RADIO SLAVE FUNCTIONS WITH TRANSMITTTER-YN-622C / YN-622C-TX ETTL /M / Multi HSS to 1/8000th 1st Curtain Sync / 2nd Curtain Sync FEC / FEB-1/3rd Increments (3 stops) Remote Flash Power-1/128-1/1 (1/3rd increments) Remote Flash Zoom 20-200mm- Auto and Manual Group Control WITH TRANSMITTER-YN560 IV / YN560-TX Remote Flash Power- 1/128-1/1 (1/3rd increments) Remote Flash Zoom 20-200mm-Auto and Manual Group Control WITH TRANSMITTER-RF-605 Fire the Flash Group Control WITH TRANSMITTER-RF-603 II / RF-603 Fire the Flash Only The YN-685 provide an HV Battery Port for attaching external high voltage battery packs, as well as a PC Sync Port To set the YN-685 apart from YongNuo's RT Radio Flash System for Canon, YongNuo have chosen to produce a completely new case design, a combination of the previous YN-568EX styling and the later YN600EX-RT. The YN-685 provide a long awaited Radio Slave Flash alternative to YongNuo's RT system, ideal for the many people already invested in the popular YN-622C TTL trigger system. One functional advantage of the YN-685 / YN-622C is the ability to control remote flash zoom length, which the RT system does not provide.