The RK4-1100 is powerful and versatile enough to handle a wide variety of on-the-run assignments like fashion, corporate work, portraiture, weddings and interiors. The RP400 pack has 3 head outlets and breaks down its output symmetrically or asymmetrically over a 6 stop range with short flash durations at a super fast 1.0 seconds recycling time at full power. A variator knob allows fine tuned exposure adjustments over 2 stops in 2/10 stop increments. Triggering options include sync cord (provided), IR or optical slave.The included RH1050 flash head has a 150W modeling light, 16ft power cable, user replaceable 1000W/s capacity flash tube and an ideal color temperature of 5400K.Although you may be tired at the end of a long shooting day, it won’t be because of your equipment. The RP400 pack weighs a mere 4.1 lb and the RH1015 flash head only 2 lb.