Walkie Talkie

The IP rating of a radio or oter device is made up of two numbers.                                  
The first number indicates the level of protection against ingress of solid objects including dust etc.
The second number (and the most important one when choosing a walkie-talkie!) is the level of protection from water or other liquids.
The higher each number is, the better the protection against solid objects or liquids getting into the radio and damaging it.