Top 10 Best knockout seal in 2026

Last Updated - 6/13/2026

🏆Best Choice

Tnisesm

Tnisesm 200Pcs 8 Sizes Nylon Plastic Hole Plugs Black 1/4" 5/16" 3/8" 1/2" 5/8" 3/4" 7/8" 1" Round Drill Hole, Flush Type Panel Knockout Locking Plugs, Furniture Cabinet Insert End Caps

9.8

ChoiceComparer.com Score

9.8

/ 10

Outstanding

Main highlights

•Round Hole Plastic Plug is made of high-quality nylon plastic conforming to RoHs standards, which is light in weight, wear-resistant and firm; Tooth design is not easy to fall off.
•The screw plastic cover is easy to install and use, simple and quick without tools. Just select the right hole plug according to the diameter of the hole plug and press it into the hole to complete the installation.
•Applicable size: 8 sizes of embedded plug sizes are 1/4 inch, 5/16 inch, 3/8 inch, 1/2 inch, 5/8 inch, 3/4 inch, 7/8 inch and 1 inch, and you can choose from a variety of sizes to deal with various problems; Please confirm the size before buying.
•Widely used: the classic multifunctional black screw cover is the perfect choice for covering, hiding and decorating holes, and will not destroy your overall decoration; Various size options, suitable for all kinds of holes, screw holes, partition holes, window frames, door panels, fences, desk and chair legs in cabinets or electrical boxes.
•Packaging includes: 200Pcs black plastic hole plugs, 8 common sizes. 50Pcs 1/4inch，40Pcs 5/16inch，30Pcs 3/8inch，25Pcs 1/2inch，20Pcs 5/8inch，15Pcs 3/4inch，10Pcs 7/8inch，10Pcs 1inch； Screw hole plugs of various sizes are placed in a transparent box with compartments to meet your various needs.

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$11.89

$13.99

-15%

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Yaocom

Yaocom 12 Pcs Knockout Seal Electrical Box Knockout Plugs Round Steel Removable Seal Various Sizes for Closure Unused Box Outlets, Compatible with Size of The Conduit Pipe(1 Inch)

9.7

ChoiceComparer.com Score

9.7

/ 10

Outstanding

Main highlights

•Quality and Durability: the knockout seal is crafted using iron material, ensuring they are robust and long lasting; They are designed to through everyday wear and tear, providing a proper solution for electrical endeavor; Available in a quantity of 12 pieces per pack, they are an ideal choice for those seeking quality and durability
•Secure and Reliable: these electrical box knockout plugs are manufactured with dimensions of about 1 inch in size; With this ideal size, they can snugly fit punching hole in an electrical box, preventing dust and debris from infiltrating, thus ensuring your electrical systems' safety and reliability
•User Friendly and Convenient: ease of use is a feature of our round steel removable seal; The design is simple and can be quickly fitted into punching hole without needing special tools or equipments; Remove the hassle from your electrical projects with these convenient knockout seals
•Multi Use Solution: the electric box knockout seal is versatile and can be applied in a variety of environments, whether that's residential or commercial buildings; They cover the exposed punching holes in the steel outlet boxes and other metal shells, making them a useful solution for many electrical tasks
•Comprehensive Package for Use: each package comes with 12 steel seal, providing a comprehensive solution for your various electrical tasks; This number ensures that you will always have a spare seal when you need it, adding to the convenience; They can cover expose tapping holes in steel outlet boxes and other metal casings

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$8.99

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Morris

Morris 21796 Type S Knockout Seal with Screw and Bar, 2-1/2", 1-Pack

9.5

ChoiceComparer.com Score

9.5

/ 10

Outstanding

Main highlights

•Type S Knockout Seals with Screw & Bar - Set screw/bar type knockout seals are inserted in open box knockouts to protect exposed wires.
•Set screw/bar type knockout seals are inserted in open box knockouts to protect exposed wires
•Used in standard, air tight or dust tight applications
•Pre-assembled screw and backer bar slides on open knockout holes without removing box devices or covers
•Steel Galvanized

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$8.98

$10.99

-18%

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Hillman

The Hillman Group 58179 2-1/2-Inch Hole Nylon Knock Out Seal, Black, 2-Pack

9.4

ChoiceComparer.com Score

9.4

/ 10

Excellent

Main highlights

•The knockout seal is ideal for electrical assemblies and can be used for covering knockout holes in electrical boxes
•The nylon knock-out seal features tool-free installation that can be placed easily by hand
•The seal features a high quality nylon that offers sturdy, reliable performance and corrosion resistance
•The gray color is designed to replicate the look of finished steel
•Comes with two seals, featuring a 2" trade size and fits a 2-1/2" diameter hole

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$4.89

$7.11

-31%

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PEUTIER

20pcs Seal Electrical Box Knockout, Removable Electrical Box Knockout Round Electrical Panel Knockout Plugs Stainless Steel Knockout Seal for Conduit Pipe (1/2in) Closure Unused Electric Box Outlets

9.2

ChoiceComparer.com Score

9.2

/ 10

Excellent

Main highlights

•Package Contents: You will receive 20 pieces of electrical box knockout, it is sufficient for your use and replacement.
•Product Size: The outer and inner diameter of electrical box knockout plugs is 27mm/1.06in and 22mm/0.86in, ensuring it fit snugly into the box with the tight.
•Quality Material: Our knockout seal is made of premium stainless steel, it is solid and not easy to break and fall off, you can use it for a long time.
•Easy to Use: The electrical knockout plug has a snap-on design. You can use it by fingertip pressure to install it easily without any special tools.
•Practical Tool: The electrical panel knockout plugs are a useful and practical tool to protect your electrical system from dust and debris. It is a perfect tool for electrical project and electrician.

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$8.39

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Sigma Engineered Solutions

Sigma Engineered Solutions ProConnex 18151 Knockout Seal 3/4-Inch, 4-Pack

9.1

ChoiceComparer.com Score

9.1

/ 10

Excellent

Main highlights

•Closes unused knockouts in a steel outlet box or metal enclosure
•For 3/4'' standard electrical box knockout
•Zinc-plated steel construction
•Includes 4 pieces per bag

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$4.96

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Mlhezy

20PCS Seal Electrical Box Knockout in 2 Sizes, Removable Round Steel Instant Knockout Plugs for Closure Unused Electric Box Outlets Holes, Snug Pocket Hole Plugs (1/2'' and 3/4'')

8.9

ChoiceComparer.com Score

8.9

/ 10

Great

Main highlights

•[Versatile and Efficient Sealing]: Our Removable Knockout Seals for Electrical Boxes offer the ultimate solution for sealing unused holes with ease and efficiency. Each set includes 20 seals, with 10 each of two sizes: Size 1 fits 1/2-inch holes, while Size 2 fits 3/4-inch holes. Experience cleaner, safer, and more efficient operations with our versatile seals.
•[Durable and Reusable Construction]: Crafted from nickel-plated carbon steel, our seals boast exceptional durability and a smooth surface for long-lasting performance. Their removable and reusable design adds convenience to your maintenance routine, ensuring reliability in every use.
•[Cost-Effective Versatility]: With two sizes included in each kit, you can address various hole sizes without exceeding your budget. Get the versatility you need for a fraction of the cost, making them a smart and cost-effective choice for your electrical projects.
•[User-Friendly Installation]: Say goodbye to complicated installations with our easy-to-use seals. No special tools or equipment required – simply fit them into the punching hole effortlessly, saving you time and effort during setup.
•[Comprehensive Set for Any Task]: Whether for residential or commercial use, our comprehensive set of 20 seals ensures you always have spares on hand when needed. Protect your electrical system with confidence, knowing that our seals provide a reliable solution for all your electrical tasks.

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$13.99

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Halex

Halex, 1-1/4 in. Knockout Seal , 60712, 1 per pack , Silver

8.8

ChoiceComparer.com Score

8.8

/ 10

Great

Main highlights

•Covers exposed knockout holes in metal enclosures such as steel outlet boxes
•1-1/4 in. opening
•Corrosion-resistant, zinc-plated steel
•For indoor or outdoor use
•Steel
•Use indoors to cover exposed holes in steel outlet boxes and other metal enclosures
•1-1/4" Knock Out Seal

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$5.70

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Sierra Pacific

Knockout Seal, Gasketed, Oil Tight Hole Seals, 1/2", Steel, Gray Painted (1)

8.6

ChoiceComparer.com Score

8.6

/ 10

Good

Main highlights

•Steel hole seal covers are painted ANSI-61 gray.
•Each set includes the Cover with weld stud, gasket, back plate and wing nut.

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$15.49

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Gardner Bender

Gardner Bender KO701C Metal Knockout Seal, ½ Inch Conduit Size, Marked Size, Rust-Proof Galvanized Steel, 16 AWG Steel, ⅜ Inch Thread, Embossed - Self Centering, For Knockout Punch / Die Conduit, Cover, 5 Pk.

8.5

ChoiceComparer.com Score

8.5

/ 10

Good

Main highlights

•Easy-to-use metal knockout seal
•Superior quality at an affordable price
•Embossed for quick self-centering in unused knockouts

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$6.31

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