Fires the slave flash exactly when the main flash occurs. Some flash settings on digital SLR`s are not compatible. Long battery life, 300 hours of use or more. If not turned OFF after use, the unit will shut down after 15 minutes of inactivity. Battery life, with limited use, is around 10 months. Pointing the sensor towards the camera flash give you
about 25 ² operating range indoors in rooms with a white ceiling. It will also trigger at much closer range from reflected light.