Installing an old work box Arlington new non-metallic device/sconce boxSAVES time it comes ready to use and it's easy to install with a 3-1/4 in standard hole saw You'll get a super secure installation too. as you push the box into the opening, its saw teeth cut a path through the drywall for the device screws. They hold the device securely in place. after installing the device, complete the job with a maxi-plate - required to fully cover the hole in the drywall.