In Star Trek: The Original Series, the compact device that lets crew members communicate with a starship from a planet is the communicator.
The original-series communicator is a handheld, flip-open communications device used by landing parties. It connects personnel on a planet with the Enterprise and can support voice communication over long distances. The prop and its distinctive opening action became one of Star Trek’s most recognizable pieces of technology.
Communicators are not the same as tricorders. A tricorder is primarily a portable sensor and data-analysis device, while a communicator is designed for transmitting and receiving messages. Later Star Trek productions use more advanced personal communicators, badges, and integrated systems, but the original handheld device remains the classic example.
The communicator also influenced real-world design culture. Its appearance is often cited as an imaginative precursor to the modern mobile phone, although the fictional device performs functions and operates over distances beyond contemporary consumer technology.