Description of Canon ST-E2 transmitter:
Power source one lithium 2CR5 battery (not included)
To find more about Canon ST-E2 transmitter visit Canon .
Canon ST-E2 transmitter Key Features:
Canon E-TTL Compatible
Built-in AutoFocus-Assist Beam
Sets and Controls Flash Rations
High-Speed FP Flash
Canon E-TTL Wireless Autoflash Control