This infrared flash trigger with a hot shoe is actually two products in one. It's got a cold shoe that slips into a standard metal shoe like the one that you'd find on a camera bracket. It also has a female PC connection on its side that can plug into a camera or another flash. Alternatively, a 1/4"-20 brass tripod socket is tapped into the bottom of the shoe, which allows you to mount it onto a light stand or a tripod. The IR sensor in this unit will recognize a typical small flash up to 70 feet away and trigger a second flash that is connected to the shoe. It will also trigger a third flash through the PC connection via a cord. $15 + $5 shipping .