Communication-related measuring instruments are devices that check the connection status of communication cables such as LAN cables. They can check continuity just by connecting a cable to a device and can check problems such as disconnection and incorrect connection easily. Handheld type products that are easy to carry are the mainstream, and pocket-sized products and products with a neck strap are also available. Basically, they use dry cell batteries or button batteries as power supplies, but you can also select products that can be charged from a USB port. For a product that can be separated into a main unit and a sub unit, insert each of the connectors at both ends of the cable into the main unit and the sub unit, which enables checking terminals in separated places easily. The types of cables and connectors that can be checked and the types of checks vary depending on the model, so it is necessary to select a product that suits the purpose.