If you need an "application kit" to work with a phone or test phone communications on lines that also carry a data signal, this is a pretty good tool for that. It doesn't have a fancy digital screen or other crazy accessories; It's basically a phone with a connector for connecting alligator clips, RJ plugs, banana clips, etc. Not for testing voltage, current, resistance, capacitance, line length, open/short, or anything similar. Just a simple phone test kit. It will make outgoing calls or allow