YONGNUO Updated YN622C II Single Transceiver HSS E-TTL Flash Trigger H-speed sync for Canon The quick lock design, you can fasten the hot shoe of this flash trigger with your camera or flash. It supports 622C communication mode ( YN-622C and YN-622C-TX) and ( RF-605C, RF-603 II and YN560-TX ). TTL mode, you can use YN-622C II, YN-622C, Canon version together, and when you use it with YN-622C-TX, it can be used as receiver. Manual mode,you can use YN-560TX, RF-603 II, RF-605C as transmitter, and use YN-622C II as receiver. It supports USB Firmware upgraded.