Two monolights offer a maximum of 300 watt/seconds each. The third monolight is 100 watt/seconds, and is useful as a hairlight or background light. Each monolight has the ability to adjust flash levels from full to 1/8 power. A 100W modeling light aids in adjustment and placement. The Impact VSD300 and EX100A are good units for occasional use by a hobbyist, or a beginning professional. Their built-in optical slave fires the flash without wires, from the light of any other flash system. This three-monolight kit includes two air-cushioned 10" light stands, a convertible stand that becomes a telescopic boom, 2 white umbrellas, a 24" square softbox, sync cord (Mini plug to PC) and soft kit case. Also included are a 16-channel radio transmitter and receiver (range 150") to enable you to trigger your system wirelessly. Impact Three Monolight Portrait Boom Kit with Case (120VAC) Specs Maximum Watt/Seconds: 300 Guide Number: 182 in feet, @ ISO 100 Recycle Time: 2 sec @ full power Flash Variability: Full to 1/8 power in 1/10 stop increments User Replaceable Flashtube: Yes Changeable Reflector: Yes Modeling Light Wattage: 100 Operating Voltage: 110-120VAC, 50/60Hz Built-in Slave Cell: Yes, 10 m range Circuit Protection: Fuse Fan Cooled: No Auto Dump: Yes - limited - strobe fires automatically as power is turned down Dimensions: 11.6 x 8.5 x 6" (29.5 x 21.6 x 15.2 cm) with 6" reflector This Impact Three Monolight Portrait Boom Kit with Case (120VAC) includes: 2 x Impact Digital Monolight 300W/s (120VAC) Impact One Monolight Kit (120VAC) Impact Multiboom Light Stand and Reflector Holder - 13" (4m) 2 x Impact White Translucent Umbrella (43") Impact Light Kit Bag (34 x 13.5 x 8") 2 x Impact Air Cushioned Light Stand, Black - 10" (3m) Impact AC 16 Channel Radio Slave Receiver (120/220V AC) Impact AC 16 Channel Radio Slave Transmitter