Free yourself from cables and optical alignment with the built-in Nissin Air System of the Nissin Di700A Flash, which provides reliable 2.4 GHz TTL triggering from up to 98' away. This system works with Canon cameras that feature E-TTL / E-TTL II metering and offers wireless slave capabilities for off-camera flash use when using the optional Air 1 Commander. The Di700A is also a very capable flash with a guide number of 177' at ISO 100 and 200mm as well as a zoom range of 24-200mm, which can be controlled manually through the Commander. A built-in wide-angle panel is available for coverage of lenses down to 16mm on full frame.