Copkim 8 Pcs 4 x 4 Inch Metal Receptacle Electrical Box Cover Square Exposed Work Receptacle Outlet Case Cover for 4 Inch Electrical Box

What it is and where it fits

I picked up the Copkim 4x4 box covers for a batch of exposed receptacles in a garage and a small commercial utility room. These are galvanized steel covers sized for standard 4-inch square (“1900”) electrical boxes and configured for two duplex receptacles. If you’re outfitting exposed work—think garages, basements, shops, or back-of-house spaces—this style of raised device cover makes for a tidy, durable, code-friendly way to put outlets on a 4-inch box without switching to finished-wall plates.

The set ships as an eight-pack in a silver galvanized finish, and mine arrived uniformly straight and clean. Hardware was included, which meant I didn’t have to dig through my bins for device screws or box screws.

Build quality and finish

The steel is stout enough that the covers don’t oil-can when you tighten the screws, and the raised sections feel rigid. Edges were deburred on the pieces I installed—no sharp lips or burrs to catch a glove or nick a conductor. The galvanizing is consistent with a satin sheen rather than a mirror polish; it hides fingerprints and the usual jobsite scuffs. I deliberately dragged a screwdriver across one to see how easily it would mark: light contact left no visible scratches; a heavier drag left a faint line but nothing that jumped out once mounted. For a piece of exposed work hardware, that’s about the right balance of durability and appearance.

A small but appreciated detail: the tapped holes and factory nuts took screws smoothly. I didn’t hit any cross-threaded holes or paint-clogged threads, which is a common frustration with lower-tier covers.

Fit and compatibility

These covers are designed for standard 4-inch square metal boxes and two duplex receptacles. Mounting holes lined up with both the box and the device straps without needing to file or slot anything. The openings match standard duplex geometry, so typical spec- and residential-grade duplex outlets sat centered and flush in the raised windows.

A quick note on format: this specific set is the two-duplex style. If you’re planning to use decorator/GFCI (rectangular) devices or a single round device, you’ll need the corresponding cover pattern. The terms “4-inch box cover” can encompass a dozen different cutouts and raise heights; double-check the cutout style and measurements against your devices before you order. For two-duplex work, these are correct.

Depth-wise, the raised profile provided ample clearance for device bodies and stranded pigtails without forcing wires. I had no trouble maintaining bend radii in 12 AWG, and I didn’t see any pressure marks on the insulation after tightening everything down.

Installation experience

Installation was straightforward:

• I pulled conductors, made up pigtails, and mounted the duplex devices to the cover first (hardware provided), then fastened the assembly to the 4-inch box.
• The device alignment to the cover windows was spot on; the receptacles sat centered with an even reveal.
• The included screws were properly sized for both device straps and the box. Threads were clean, and the screw heads didn’t cam out under normal driver pressure.

Each cover took just a few minutes once the box wiring was finished. Because the edges were smooth and the steel had some stiffness, I didn’t feel the need to baby them during installation. Everything tightened down square, and the cover-to-box seam sat tight and even at all four corners.

If you’re new to exposed work on 4-inch boxes, a couple of tips:

• Use the correct box fill and make your pigtails a touch shorter than you might in a deep gang box; you want conductors folding neatly behind the devices so the cover lays flat.
• If you’re in a damp location, pair the box with the right gasket or use a weatherproof cover/box combo. These covers themselves are metal and durable but aren’t a weatherproof solution by default.
• Bond the metal box and ensure continuity through the device strap and cover where required by your jurisdiction.

Day-to-day use and appearance

Once up, the finish has a clean, industrial look. In the garage and utility room, the silver galvanized surface blended with conduit and EMT, making the runs look intentional rather than improvised. The covers wipe down easily with a rag—dust and drywall residue don’t cling, and I didn’t see rust starting at the edges after a few weeks in a non-conditioned space.

Because these are exposed work covers, they’re not what you’d choose for a finished living room wall. But for shops and service areas, they strike the right balance: clean, professional, and tough.

Consistency across the pack

All eight pieces in my box were consistent: same finish, same cutout tolerance, same screw fit, and no warping. I’ve had mixed experiences with bulk packs from off-brand sellers where the first two are perfect and the fifth is out of square or the mounting holes drift. That wasn’t the case here. If you’re doing a run of boxes on a single wall, consistent geometry matters; it keeps devices aligned and the visual line straight.

Limitations and caveats

• Cutout style matters. This set is for two duplex receptacles. If your plan involves decorator/GFCI devices, switches, or specialty round devices, choose a cover with the correct opening pattern. It’s an easy place to make a wrong assumption.
• Not weatherproof as-is. For wet locations, you’ll want a weatherproof cover and box system. These are great for dry or damp indoor spaces when paired with appropriate boxes and gaskets but aren’t a substitute for an in-use or bell-style cover outside.
• No fancy finishes. The galvanized silver is practical, not decorative. If you need color-matched or stainless covers for an architectural space, you’ll look elsewhere.

None of these are faults; they’re just about picking the right cover for the job.

Value

Buying covers one at a time from a supply house adds up fast. In an eight-pack, the per-piece cost becomes much more reasonable, and having a few extras on the shelf saves a run to the store when you add a circuit later. Given the build quality, the included hardware, and the consistent fit, the pack makes sense for homeowners tackling a garage upgrade as well as pros outfitting a small job.

Who it’s best for

• Homeowners upgrading a garage, basement workshop, or utility room with exposed conduit and 4-inch square boxes.
• Electricians and facility techs who need a reliable, consistent cover for two-duplex runs in back-of-house spaces.
• Makerspaces and small shops that want durable, easy-to-clean covers that look neat and hold up to abuse.

If you’re doing finished residential walls or need decorator devices, this isn’t your match; pick a different cutout or a standard 1- or 2-gang device box with trim plates.

The bottom line

The Copkim 4x4 box covers hit the right notes: solid galvanized steel, clean edges, consistent openings, and provided hardware that actually fits. They install quickly, keep exposed work tidy, and hold up to the bumps and scrapes that go with shops and utility spaces. I didn’t run into alignment quirks, burrs, or thread problems, which are the usual time-wasters on low-cost covers.

Recommendation: I recommend these for anyone outfitting two-duplex outlets on standard 4-inch square boxes in dry or damp indoor locations. They’re a cost-effective, durable way to finish exposed work with a professional look, and the eight-pack makes sense whether you’re doing a single garage wall or a small facility upgrade. Just make sure you’re selecting the right cutout style for your devices and the right enclosure system for your environment, and these will serve you well.