With the LINDY RJ-45 Port Blocker, you can quickly block open network ports & easily prevent users from connecting cables, devices or inserting foreign objects without permission. This helps protect against unauthorised access to a network or system, as well as preventing unintentional or malicious damage to ports. It can also act as a visual cue, showing inactive or disconnected ports. The semi-permanent RJ-45 Port Blocker is made up of a molded plastic blocking cap that plugs securely into the RJ-45 port with a special insertion key. The blocker latches into the RJ-45 just as a network cable would & remains in place until removed using the insertion key (not included, see part number 40470). To use, simply attach a blocker to the key & plug it into the port. Hold the blocker in place & pull away the Key. To remove simply insert the Key back into the blocker until it clicks & pull it away. Easy! Security Note: This Port Blocker will only act as a a basic physical & visual deterrent to tampering. It will not prevent a determined attacker, intent on gaining physical access to a RJ-45 port.