The PocketWizard Plus III Transceiver is a radio triggering transceiver/receiver for remote firing of flashes and strobes. It can also be used to remotely trigger shutters with the appropriate PocketWizard shutter motor cord (not included). It connects to your camera with either a sync cable (see Rental Includes for more) or via your camera's hot shoe. It connects to your flash or strobe by sync cable. Each Plus III is both a transceiver/receiver so they are interchangeable on your camera and strobe but you will need (2) PocketWizards for your off-camera strobe firing to work unless your strobe has a power pack with a built-in receiver. This rental comes with only (1) Plus III.