SMDV FlashWave-2 Digital Radio Slave (Flash Trigger) Set FlashWave-2 is one of the most compact and reliable flash slave (flash trigger) available. With the hot shoe built in to the receiver unit, there is no need to buy or carry any cables, adapters or accessories. The package contains one transmitter (TX) and one receiver (RX) unit. The receiver uses two standard AAA batteries and the transmitter uses one standard A23 (12V) battery. > Simple, Small, Reliable > Hot shoe built into the receiver > No need for extra cables or adapters > Up to 250 feet operating range > 10 Channels. > Max sync speed of 1/200s > Built-in 1/4" tripod thread