The Canon WFT-E4A Wireless File Transmitter allows you to wirelessly transfer your files from the EOS 5D Mark II to a secure network. In addition, it also serves as a vertical grip, duplicating basic camera controls for easier vertical shooting.
The WFT-E4A can transfer images wirelessly through either 802.11b or g protocols, and has a USB connection for situations where wireless access is limited, or impractical.
It is also equipped with a powerful antenna, capable of transmission up to 150 feet. The Wireless File Transmitter can connect to a third-party GPS device via the USB connection, providing the ability to attach GPS information directly into the image's EXIF data, or you can plug a compatible USB 2.0 hard drive into the transmitter's USB port, and actually shoot directly to a large portable hard drive.
The WFT-E4A is powered by the LP-E6 lithium-ion battery, which does not supply any power to the camera itself. It also allows you to check the remaining capacity on the camera's power source info screen.
Transfer images wirelessly through either 802.11b or g protocols
Transmits up to 150'
Connects to third-party GPS devices via the USB connection