Shanny SN-E3-RF 2.4G Wireless Radio Transceiver for SN600C-RF Flash,TTL trigger,LCD panel for Canon &times;2 High speed sync 1/8000s Flash Mode ETTL/M/MULTI Sync Mode HSS, 1st Curtain Sync / 2nd Curtain Sync Radio Channels Support 15 Radio Channels (CH 01~CH15 ) Flash Zoom Support manual and auto zooming