Tondiamo 20 Pcs Black Wall Insulation Gasket Rectangle Wall Plate Outlet Sealers Foam Replacement Weatherproof Gasket Sealer Energy Saving for Electrical Outlet Plates Switch Covers

Why I tried these gaskets

A couple of cold, windy days were all it took to remind me how much air can sneak through switch and outlet plates on exterior walls. Stand near a southwest-facing wall in winter and you can actually feel a little chill around the plates. That’s low-hanging fruit for energy savings. I picked up a pack of Tondiamo’s black foam gaskets to see how much draft reduction I could get with a quick afternoon’s work.

What’s in the pack

This kit includes 20 EVA foam gaskets at about 3.0 mm thick (roughly 1/8 inch). They’re split across three plate sizes—single-gang (63 × 107 mm), double-gang (108 × 109 mm), and triple-gang (108 × 157 mm). Each sheet has a punch-out grid that covers most common device layouts: single or double outlets, decorator/rocker, toggles, and combinations up to three devices wide. In other words, you pick the sheet that matches your gang count, pop out the sections that match your devices, and the gasket sits behind the cover plate.

The material is EVA foam, which is compressible, springy, and naturally closed-cell—good traits for sealing large but irregular gaps.

Installation and fit

If you’ve installed wall plates, you can install these. My process:

• Turn off the breaker for the circuit (yes, it’s only the cover plate, but it’s still best practice).
• Remove the wall plate.
• Test-fit the appropriate gasket sheet and punch out the right cutouts.
• Trim, if needed, with a sharp utility knife on a cutting board.
• Reinstall the plate, tightening screws evenly to compress the foam.

On standard decorator switches and duplex outlets, the cutouts lined up cleanly. The foam tears by hand, but for cleaner edges—especially around tight toggle openings—an X-Acto blade gave me a neater result and kept the foam from stretching. For multi-gang plates with mixed devices, I appreciated the flexible grid: I set up a two-gang with a toggle and a GFCI in under two minutes.

A couple of notes from my install:

• Thickness: At 3 mm, these seal well, but if your walls aren’t perfectly flat or your plate is thin, the plate can sit slightly proud. Tighten the screws gradually and stop before bowing the plate. Sturdier nylon or metal plates help keep things flush.
• Color: The gaskets are black. If you have light-colored plates and visible wall gaps around the plate edges, a hairline of black can show. Not an issue on tight-fitting plates or darker walls; otherwise, a quick paint touch-up or a bead of caulk around the plate perimeter hides it.
• Specialty plates: Snap-on “no screw” nightlight plates and smart covers that use the plate cavity may not play nicely; the foam occupies that space. Traditional screw-on plates are fine.

Total time was about 1–2 minutes per device once I found a rhythm.

Performance

The benefit was immediate: drafts around exterior outlets and a three-gang switch cluster dropped to essentially nothing by feel. On a windy day, I checked with a simple IR spot thermometer; surface temperatures at the plate edges were noticeably closer to the room average than before. That’s consistent with what you’d expect when you cut off the convective path through the plate openings and around the devices.

A quick reality check: these gaskets address air that migrates through the device openings and plate perimeter. They don’t seal the junction box to the drywall or the box to the sheathing. If you’re chasing deeper envelope performance, you’ll also want to caulk the box perimeter, use box extenders on overcut drywall, and seal exterior penetrations. But as a fast, low-effort improvement, these gaskets deliver exactly what they should: less draft, fewer cold spots, and a small assist to heating and cooling efficiency.

Material quality

EVA foam is a good choice for this application. It compresses to fill small irregularities and springs back when you remove the plate, so you can re-fit without shredding. I didn’t see crumbling or permanent compression after a couple of re-installs. The edges remained intact where I cut with a sharp blade; rough hand-tears can leave fuzzier edges, but it’s cosmetic and hidden behind the plate.

There’s no adhesive—compression does the work—which is fine. Adhesive-backed seals tend to make future plate changes messy. Here, the gasket stays put well enough during reassembly, and if it shifts, gravity and the plate pressure center it as you tighten the screws.

Compatibility and coverage

The kit handled everything in my test areas:

• Duplex outlets (standard and tamper-resistant)
• Decorator/rocker switches, including GFCIs
• Toggle switches
• Two- and three-gang combinations with mixed devices

One limitation is the assortment count. Homes typically have more single-gang devices than triples, and this pack splits 10 single-gang sheets with 5 doubles and 5 triples. You can cut a triple down to cover a double or single, but you’ll waste some foam. That said, the flexibility of the punch-out grid meant I never hit a configuration I couldn’t cover.

If you use oversize or “jumbo” plates to hide wall damage, the single-gang size here is the standard footprint. It will still work, but the foam won’t reach the oversize plate edge. That’s rarely a functional issue, as the seal is most useful around the device opening.

What I liked

• Effective draft reduction: The room felt more even, especially near exterior switch banks.
• Flexible cutouts: One kit covered toggles, rockers, outlets, and mixed multi-gang boxes without hunting for specific shapes.
• Good thickness: 3 mm is a sweet spot—thick enough to seal, thin enough to install quickly.
• Durable EVA: Doesn’t crumble, easy to trim cleanly, and re-usable during plate swaps.
• Straightforward install: It’s a low-risk DIY with common tools.

What could be improved

• Plate flushness: On slightly warped walls or thin plates, the foam can keep the plate a touch proud. Rigid plates or careful screw tension solve this, but it’s worth noting.
• Color choice: Black can telegraph through micro-gaps around light plates on light walls. A white or gray option would broaden appeal.
• Assortment balance: More single-gang sheets and fewer triple-gang sheets would better match typical homes and reduce trimming waste.

Safety and best practices

• Kill the power at the breaker. You’re only removing the plate, but it’s easy to slip a screwdriver where you shouldn’t.
• Keep the foam outside the electrical box. The goal is to seal behind the plate, not to stuff the box. Don’t rely on these for electrical insulation or fire protection.
• Don’t overtighten plate screws. If the plate bows, back off a quarter turn; the foam will still seal.

Value

For the cost of a few coffees, you get enough gaskets to cover a big chunk of a small home—or all the key exterior walls in a larger one. The package flexibility matters: I didn’t have to stock separate bags for toggles vs. rockers vs. outlets, and that avoids half-used packs sitting in a drawer. Given the ease of installation and the immediate comfort gain, it’s an excellent cost-to-benefit ratio.

The bottom line

These Tondiamo gaskets do exactly what you want from a simple weatherization upgrade: they cut drafts at outlets and switches, install quickly, and adapt to nearly any plate layout you’ll encounter. They’re not a silver bullet for air sealing the entire wall assembly, but they’re a fast, low-cost step that makes a noticeable difference in comfort and marginal energy use. The black color and plate flushness are minor trade-offs, and the assortment could lean more heavily toward single-gang sheets, but those are small quibbles for what you get.

Recommendation: I recommend these gaskets for homeowners and renters who want a quick, inexpensive draft fix around outlets and switches, especially on exterior walls or windward exposures. They’re easy to install, broadly compatible, and effective—exactly the kind of low-effort upgrade that pays you back in comfort immediately and on your utility bill over time.