The Dorr RS Transceiver Device is a flash trigger or receiver for Canon camera flashes and studio flashes. It features a remote camera release as senser of the receiver. It also has a wireless radio transmission which covers up to 400m. The manual flash release can be used via hot shoe contact. The Dorr RS Transceiver has 4 radio channels in 3 groups and requires 2x1.5v AA batteries. Any number of RS radio transmitter and receiver can be combined and synchronized trigger. This kit comes with 1 device for expansion of the 371560 Transceiver Kit.