The locking function on the device prevents tampering and keeps your devices from moving out of place. Many locking devices operate with a key, which allows only the person with the key to unlock the device. Other locking devices use a twist lock to secure themselves. Locking devices include electrical plugs, switches, connectors, and outlets. Common applications include environments with small children, such as a school, or high-security locations such as prisons. They also see use in applications where moving parts might easily unplug themselves.