The Wireless trigger let you start & stop captures in QTM. The trigger also has an event button for creating events. The package consists of two parts: a trigger and an usb receiver that you plug into the computer running QTM. Please note that the wireless trigger or keyboard cannot be used to trigger external equipment (e.g. EMG devices). Simultaneous triggering of the camera system and external devices require the use of an external trigger connected to a trigger port.