Police box
A police box is a telephone box for use by members of the police. Police boxes pre-date the modern era, where every police officer (in developed countries) is likely to carry a two-way radio. They were used by officers "on the beat" to keep in contact with the local police station, reporting anything unusual, requesting help if necessary, etc.The police box telephone could also be used by members of the public to contact a police station in an emergency.
In Britain police boxes were usually blue. As well as a telephone they contained essential equipment such as an incident book and a first aid kit.
There are very few police boxes left in Britain today. Some of those remaining have been converted into high street coffee bars.
In fiction, one famous police box is the TARDIS in the British television series Doctor Who.