Yongnuo RF-603C3-INT Wireless Remote Flash Trigger for Canon 1D 1DS 5D 5DII LF239
The brand new RF-603 is a remote shutter release as well as a multi-functional radio flash trigger which can synchronously trigger flashes and studio strobes. Through the transceiver based system each item can be used flexibly as trigger or receiver. Only 2 AAA batteries are required as power source for each item.The 2.4GHz wireless frequency is suitable in most countries and guarantees high speed, distance and stability. Within capacious areas, the remote control distance may reach to 100m. The synchronization speed can reach to 1/320, depending on the situation it may reach to 1/250 or less.A set consist of 2 equal transceivers. Both of them can be a receiver as well as transmitter. It can trigger 1 flash with one set, since one serves as trigger and one as receiver. You can also buy additional transceivers to trigger 2 or more flashes at the same time.  Includes (2) RF-603 transeivers (1) C3 shutter release cord