Features: 1) Output power: 300ws 2) Flash guide No: 55GN 3) Output control range: 1/32~1/1 Infinitely variable 4) Halogen modeling lamp: 150W 5) Recycling time: 0.8 ~ 2.5s 6) Flash duration: 1/800 - 1/1200s 7) Modeling light working mode: full power, proportional flash and modeling light 8) Recycling indicate: Buzz/Modeling light indication 9) Working voltage: 170 ~ 240V auto voltage regulator circuit 10) Flash triggering method: Photocell/Sync cable/Test button 11) Triggering voltage: 12V low voltage trigger 12) Cooling fan: No