Radio-frequency transmitter and receiver set lets you trigger your studio flash setup in a studio or on location without PC cords, and without concern about cord length or other cameras setting off your lights. It has a range of up to 85 feet without the limitations of line-of-sight like infrared triggers, so the flash can be positioned freely. Any of 4 radio frequencies can be selected for trouble-free flash synchronizing without interference from other nearby devices. The transmitter mounts on a camera's hot shoe mount, or use it on a flash bracket with the PC cord that is included. Receiver has an attached 1/4" phono plug cord to connect directly to many monolights and other studio flashes that use this type of PC cord connection. An adapter that converts the 1/4" plug to a 3.5mm miniplug is included. The receiver also has a PC terminal for connecting to flash cords from other types of flashes. Use with an advanced studio system or with a simple camera-mount flash, this flash trigger works with all types. You can certainly spend a lot more and get more bells and whistles, but this is the set you need for basic, dependable flash firing. Very compact unit has low power consumption, so the user-replaceable battery installed in transmitter is good for 20,000 flashes. Receiver is powered by (2) AAA batteries, not included, for up to 30,000 flashes.