This device is a wireless camera scanner with signal receiving and playing functions..It can scan signals with band width in scope 900MHz~2700MHz from wireless camera. When it scanned a signal in scope, its small screen would indicate signal bandwidth number.If you want to get view of what wireless camera is capturing, press Lock key, image will appear on large screen. You can also get view of image by connecting it to a TV set through A/V OUT lord. Its portable design makes people who is long time restricted in monitoring room enjoy flexible activities. It can also be used as a camera detector.