Supports optical transmission and wireless radio transmission flash shooting the YN600EX-RT II can used as master unit to control the flash mode exposure compensation flash ratio number of stroboscopic and stroboscopic frequency.</br>Supports wireless radio transmission flash shooting cooperate with the YN600EX-RT(II)Canon 600EX-RT(II)/430EXIIIone YN600EX-RT II can used as set-top master unit or remote slave unittotally 15 channels for option realize TTL manual flash and stroboscopic flash.</br>In the optical transmission flash shooting the YN600EX-RT II can be used as master unit to trigger the YONGNUO and Canon EX series flash (excluding the YN585EX)supports 4 channels realize wireless TTL manual flash and stroboscopic flash.</br>One YN600EX-RT II can respectively receive the wireless signal of master unit YN600EX-RT IIYN568EX II600EX(II)-RT580EX II C command and Canon 7D/60D/600D cameras built-in flash wireless signal realize wireless TTL manual flash and stroboscopic flash.</br>YN600EX-RT II as professional creative high guide number speedlite supports TTL/M/Multi flash and can realize TTL?? manual flash?? the highest shutter synchronous speed is up to 1/8000.</br></br>Product Description</br></br><p>The upgraded version YN600EX-RT II?? compared with the first version?? the only difference is it supports Canon optical transmission wireless master flash function.</p> The YN600EX-RT II equipped with USB interface?? supports firmware upgrade?? you can download the upgrade firmware through the Yongnuo official website to upgrade the flash.<br/> The YN600EX-RT II Supports auto and manual zooming?? the flash coverage can be changed between AUTO?? 20~200mm.<br/> The YN600EX-RT II can be triggered by the camera set-top?? PC synchronous trigger?? wireless optical/radio remote trigger.<br/> It just