Each monolight has a digital readout coupled with its four-stop power variator. It accepts Bowens monolight reflectors and head accessories. The VSD160 has cushioned touch-pad function control buttons. Power is adjustable in 1/10 stop increments, from full to 1/8 power. Its model light intensity may be controlled coupled to, or independent from the strobe power levels you select.The Impact VSD160 is a good choice for building a system - its built-in optical slave fires the flash without wires, from the light of any other flash system. Its flashtube is good for tens of thousands of pops, and is replaceable. This two monolight kit includes air cushioned light stands that rise to a maximum of 10 feet, 43" white umbrellas, and sync cord (Mini plug to PC).Impact Two Monolight Softbox Kit (120VAC) Specs Maximum Watt/Seconds: 160 Guide Number: 115 in feet, @ ISO 100 at 10 feet 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: 60 Flash Ready Indicator: LED on test button 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 7" (29.5 x 21.5 x 17.7cm) with 7" reflector Weight: 3.5 lbs (1.6kg) Softbox Size: 24 x 32" (60 x 80 cm) Shape: Rectangle Compatibility: Any standard monolight (not hot lights) Removable Face: Yes Removable Baffle: Yes Accepts Grids: Yes Required Speed: Ring Bowens style - included This Impact Two Monolight Softbox Kit (120VAC) includes: 2 x Impact Digital Monolight 160W/s (120VAC) 2 x Impact Softbox - 24 x 32" (61 x 80cm) 2 x Impact Air Cushioned Light Stand, Black - 10" (3m)