This FC30 frequency counters are easy to use, easy to see, and easy to mount. Their 6 digit display is bigger than most displays we've seen, making it easy to read from a distance. Comes with a dim button on the front to tone down the LED lights so they're not too bright at night. Attached will be a flat plug to attach to the frequency counter output jack on compatible radios. If you're using that connection you shouldn't need an external power connection, the counter does come with a power cord and cig plug connection. There's an RCA jack in the back that would allow you to use the frequency counter with non-compatible devices, but it would only read on TX and the extra wire needed to sense the transmitted frequency is not included.