The Odin Wireless TTL Receiver works with Canon camera and flash systems for reliable wireless radio control over your flash units. This receiver works up to 328' from the transmitter. The Odin wireless triggering system allows for control over 4 channels and 3 groups, setting multiple flashes settings individually. Another feature of the Odin system is a maximum sync speed of 1/8000 second. Also, it features a USB port for updating the firmware on your unit and it runs on 2 AA batteries.