Yongnuo Wireless Speedlite Transmitter for Canon Cameras Yongnuo Wireless Speedlite Transmitter for Canon - USB to Mini Cable - USB to 3-Pin Cable - Instruction Manual - Yongnuo 1 Year Limited Warranty Two-way 2.4G radio communication, fully compatible with ST-E3-RT/600EX-RT 15 Physical Channels, 1 Auto Channel, Up to 10,000 customizable photographer ID Transmission Range: 100M Multi YN-E3-RT can share slave flashes