... transmission-line system of electric power waves.The built in slave trigger will fire the flash when another flash fires. ... for accent, highlights, fill light, bounce light.This AC Slave can be triggered in perfect syncwith your on camera flash ... Power: 45W Guide number: 28m / 90ftAngle of Illumination: 55°Triggering: slave, sync, flashRecycle Time: 8s Color Temperature: 5600kFlash Duration 1/1000 ...