It is an important tool for communication and distress in emergency situations. It can transmit information through radio waves to help people stay in touch and get help when traditional communication networks fail. It plays an irreplaceable role in ensuring the safety of people's lives and property. It can not only provide timely communication support in emergency situations, but also help rescuers quickly locate the location of distress and improve rescue efficiency.

It is a radio communication equipment designed for military use with a high degree of reliability and durability. It can work stably under harsh environmental conditions and is suitable for use in various complex battlefield environments. The device usually uses advanced encryption technology to ensure the security and confidentiality of communication. Support a variety of communication modes, including voice and data transmission, to meet the diverse needs of modern military communications. It has good anti-interference ability and can maintain a stable communication connection in the battlefield with complex electromagnetic environment. Its battery life is strong, can work for a long time without charging, and is suitable for long-term field missions.

It is a telephone facility set up in public places, mainly used to provide public communication services. It originated in the industrial countries in the early 20th century and was widely used in the middle of the 20th century. It usually consists of a closed or semi-closed kiosk and a built-in telephone, which is designed with ergonomics in mind to ensure that the user can talk comfortably while standing. The design not only focuses on functionality, but also takes into account the beauty and practicality. Modern telephone booths usually adopt a simple and generous design style in appearance to integrate into the urban environment. However, with the popularity of mobile communications, the frequency of use of telephone booths has declined.

Mobile phone, all known as "handheld mobile phone", "handheld wireless phone", also known as mobile phone or wireless phone, commonly known as "mobile phone". It is essentially a communication tool. In the early days, it was commonly known as "Big Brother". It is a portable telephone terminal that can be used in a wide range. It was first developed from the battlefield mobile phone manufactured by Bell Labs in 1940. In 1973, Motorola engineer Martin Cooper invented the world's first commercial mobile phone.

Baofeng UV-S9 is a three band walkie talkie equipped with a 2200mAh lithium-ion battery. The package includes a dual frequency high gain antenna and a 220-225 MHz single frequency antenna.

A telephone booth is a small house standing on the street with a public telephone inside, which usually requires payment. Telephone booths are usually equipped with transparent or small window shutters to protect the privacy of users while also letting them know if the phone is in use. In some areas, telephone booths will display telephone directories for users to access.

Telegraph is a device used to send and receive telegraphs. In 1835, after three years of research by American painter Morse, the first telegraph came out. Morse successfully replaced human words with the "on", "off" and "long and short" of current. This is the famous Morse code. The invention of the telegraph opened the prelude to the era of telecommunications and created the history of human use of electricity to transmit information. China secretly opened the telegraph in Shanghai in 1871, Li Hongzhang built the first military telegraph line in the mainland in 1879, then opened the Tianjin-Shanghai telegraph line, and set up the General Telegraph Administration in Tianjin.