The SF-DSXN40 Mini Slave Flash with Hot Shoe from Impact is a DC flash unit that is a good choice for a fill light, hair light, side light or background light and of course, for use as a a small light source for single subjects or small groups of people. It can be used as a master flash mounted on your camera's shoe or as an off-camera slave flash, triggered by another flash, thanks to its optical slave sensor. A small tilting bracket is built into the housing for positioning or you can use the built-in 1/4"-20 threaded socket to mount the flash to a tripod or other threaded accessory. The SF-DSXN40 gets about 200 full power flashes from a set of 2 AA batteries and has a range of 33 feet.