Based on a design of call box introduced from the 1920s, in real life they contained a phone for use by the public in an emergency, and police officers could use them as miniature police stations, with facilities inside for compiling reports, taking lunch breaks and even temporarily holding suspects until assistance arrived!
This is a nice and simple kit to assemble, moulded in appropriately-coloured dark blue, and supplied with waterslide decals to complete the details.