The new RF-603 II is an improved version of the RF-603. It is a remote trigger and a multifunctional trigger that can trigger flashes and studio flashes simultaneously. Thanks to the transceiver-based system, each element can be used flexibly as a trigger or receiver. Only 2 AAA batteries are needed as a power source for each item. The 2.4 GHz wireless frequency is suitable for most countries and guarantees high speed, distance and stability. In wide areas, the remote control distance can reach 100 m. The synchronisation speed can reach 1/320, depending on the situation. Compatible with: Canon 7D 6D 5D Mark III 5D Mark II 5D 1D 50D