The PocketWizard CM-N3-ACC-1 1' Pre-Trigger Remote Cable is used for remotely triggering Canon cameras equipped with a N3 Remote shutter release terminal and controlling half-press function using certain PocketWizard radios. This is a special remote motor drive cable called a Pre-Trigger Cable. A Pre-Trigger cable controls both the half-press and full-press function of your remote camera's shutter release. When a camera is "pre-triggered", it is like holding your camera's shutter release button in the half-pressed or metering/focusing position. This ACC cable allows a compatible PocketWizard radio to independently control both half-press and full-press functions.