SMDV FlashQuick-II Flash Trigger & Release, Wireless Digital Radio Remote Flash Slave with Hot Shoe - Transmitter and Receiver Set Simple, Small, and Reliable wireless flash trigger. Max Sync speed of 1/250s and Max range of up to 180 meters (approx. 600 ft.) Built-in hot shoe and 1/4" tripod thread on the receiver unit for mounting on a tripod or light stand. 2.4GHz operating frequency & 16 easy selectable channels. Convenient use of readily available AAA batteries in both transmitter and receiver.