The USB (Universal Serial Bus) Port Blocker means that you can deny access to any USB (Universal Serial Bus) socket. This is useful to stop flash drives & external hard drives being connected to a computer or server to copy sensitive data, stop the delivery of viruses, keyloggers & other malicious programs. It will also stop people connecting & charging mobile devices. Insert lock into a USB (Universal Serial Bus) port with the key Squeeze the side buttons & pull out To remove the lock, insert the key into the USB (Universal Serial Bus) lock & pull out without squeezing the side buttons. Once the blocker is in place it will be very difficult to remove without damaging the USB (Universal Serial Bus) port unless you have the key.