ProMaster SM180 Studio Monolight Flash Head The ProMaster SM180 Studio Monolight is a great choice for the aspiring studio photographer. The powerful 180 watt second head provides good light with variable power, modeling lamp, 4 channel wireless triggering and an optical slave all at an affordable price. Power: 180 watt second (joule) at full power Guide Number: 151 /46m @ 100 ISO Color Temperature: 5600k  100k Accepts Bowens mount type accessories