Which of the following is NOT counted towards box fill?

In the context of electrical box fill calculations, a device cover does not contribute to the overall volume of space utilized within a junction box or outlet box. The term "box fill" pertains specifically to the internal dimensions and capacity of a box, as well as the devices and fittings that occupy that space.

When calculating box fill, you consider items like range receptacles, fittings, and switches, as they all occupy volume inside the box. Each of these components adds to the total volume, potentially leading to code violations if the box is deemed overfilled.

Device covers, on the other hand, serve as protective or decorative outer coverings for devices but do not actually take up space inside the box where electrical connections occur. Their primary function is to ensure safety and aesthetics rather than contributing to the internal volume of the box. Therefore, when determining how much space is filled in an electrical box, device covers are not included in the calculation, making this the correct answer to the question.