The Phottix Odin Wireless TTL Trigger Set provides wireless flash triggering with Nikon I-TTL functionality. This set includes the TCU transmitter and a receiver. These devices operate on a frequency of 2. 4GHz and have a range of approximately 328' for reliable triggering over distance. For setting up your flash units, you have access to 4 channels and 3 groups for ratios and manual settings. This allows for complete control over your lighting setup. Additionally, the Odin system can sync with your camera's shutter up to 1/8000 second. Another feature of the Odin wireless triggering system is the inclusion of USB ports to install firmware updates. Also, it can be used with older Strato-series receivers and each component runs on 2 AA batteries.