Arlington In Box Recessed Cover Kit
Arlington’s recessed In Box Cover Kits offer the best way to install a receptacle in their FLBC4500 floor box for new concrete (sold separately) and other manufacturers’ boxes.
In Box is recessed and installs into the can so they look great – and reduce the trip hazard caused by plugs sticking out of the box. You can also have power and low voltage in the same box.
Available with metal flanges in brass or nickel – And plastic in light almond, gray, caramel, black and brown.
http://www.aifittings.com/catalog/floor-boxes/in-box-cover-kit-for-concrete-floor-box/