There are a wide array of radios and walkie talkies available for use.
These very light walkie talkies are great for grabbing and taking with you. By default these are set to Channel 3 with “privacy code” 29.
It’s recommended to take a walkie talkie with you if you go out wandering or picnicking.
There are lots of ham radios available but you must be licensed to use them. But the tests are rather doable!