I was given a pair of small walkie-talkie radios a while ago. They are very useful when I am working in one of my fields. They come as a pair and I have one and my wife the other.
They have a range of about 1 mile but it is line of sight. So they don't work if one is behind a building or below the horizon.
We occasionally get bits of other peoples conversations. However, the radios have several channels so we just change to another when the interference gets annoying.
The other issue with these radios is their battery life. These radios have 3 AAA batteries in (each) and they last about 8 hours. It would be nice to have radios with a longer life battery which can be recharged (like a mobile phone) but we will continue to use what we have while they work. Replacement batteries are easy to get and not too expensive if you buy supermarket ones in a reasonable quantity.
If the idea sounds interesting, Google 'walkie-talkie' and you will get a lot of product offers. Choose the best you can afford. Some are weather proof, and some have other features like more channels and bigger batteries. A socket for earphones would be nice to allow you to hear the radio when wearing ear defenders while working a noisy machine (chainsaw/strimmer/tractor).
NN