Amazon.com : Canon ST-E2 Speedlite Transmitter for Canon 580EX II, 430EX, 430EX II Speedlites : On C
The Canon 2478A002 ST-E2 Speedlite Transmitter is a dedicated clip-on transmitter for E-TTL / E-TTL II wireless flash system. The auto flash transmitter can control an unlimited number of 420EX, 430EX, 550EX and 580EX flashes, in two separate groups; A an...