Lanberg's RJ45 feed-thru keystone connector can be used to build networks for both surface and flush-mounted versions of keystone boxes (by placing them inside). On top of that, this product is also designed to fill blank 10" and / or 19" modular patch panels. Moreover, this particular network accessory also works as a normal connector - to connect two wires terminated with male RJ45 8p8c connectors.