That's an ONT cover ( box ) not the ONT itself, that is behind the right hand cover inside which is secured with a screw, the side you can access is not screwed shut, simply lift the tab ( may be tight but you shouldn't break it ). Google images suggest that there is a small lip on the bottom of the smaller section that pulls forward, allowing the cover to open along the hinged top. A cable box connects devices (TV, modem, etc) of a house or building to the service provider. Keep reading to learn their names and functions. The other option is to. Our Full Fibre service uses an Ethernet cable to connect your hub to the Openreach modem (also called a Fibre box, or ONT), not a phone socket. The modem is a small box with lights plugged into a power socket, which our engineer installed inside your home.