The $26.95 Signal Launcher from Spy Gear works pretty much the same manner as how those flares function in movies, where a stranded Marine calls for help by popping one, hoping that some of his mates will be in the vicinity to offer assistance.

It comes with a whistling rocket sound to alert your fellow agents (as well as enemies, I might add). There are three foam signal rockets for you to come up with your own color codes (ooh, how exciting). It all works on manual power, so there is no need to rush to the store to stock up a supply of fresh batteries.

Source: Signal Launcher