Knockout Seals

Metallics Knock-out Seal 1-1/2" 3-Piece Steel Zinc Quick-Seal

Model: MET-150KOS

Metallics Industries Knock-out Seal 1-1/2" 3-Piece Steel Zinc Quick-SealProfessional Electrical Panel Box Sealing SolutionThe Metallics Industries Knock-out Seal 1-1/2" delivers exceptional...

Metallics

$55.90

$10.03 Sale
Metallics Knock-out Seal 1-1/4" 3-Piece Steel Zinc Quick-Seal

Model: MET-125KOS

Metallics Industries Knock-out Seal 1-1/4" 3-Piece Steel Zinc Quick-SealProfessional Electrical Panel Box Sealing SolutionThe Metallics Industries Knock-out Seal 1-1/4" delivers exceptional...

Metallics

$52.86

$4.77 Sale
Metallics Knock-out Seal 2" 3-Piece Steel Zinc Quick-Seal

Model: MET-200KOS

Metallics Industries Knock-out Seal 2" 3-Piece Steel Zinc Quick-SealProfessional Electrical Panel Box Sealing SolutionThe Metallics Industries Knock-out Seal 2" delivers exceptional performance and...

Metallics

$55.82

$8.69 Sale
Metallics Knock-out Seal 3-1/2" 3-Piece Steel Zinc Quick-Seal

Model: MET-350KOS

Metallics Industries Knock-out Seal 3-1/2" 3-Piece Steel Zinc Quick-SealProfessional Electrical Panel Box Sealing SolutionThe Metallics Industries Knock-out Seal 3-1/2" delivers exceptional...

Metallics

$75.67

$40.39 Sale
Metallics Knock-out Seal 3-Piece Steel Zinc 6" x 6" x 1.1"

Model: MET-300KOS

Metallics Industries Knock-out Seal 3-Piece Steel ZincProfessional Electrical Panel Box Sealing SolutionThe Metallics Industries Knock-out Seal 3-Piece delivers exceptional performance and...

Metallics

$58.27

$13.11 Sale
Metallics Knock-out Seal 4" 3-Piece Steel Zinc Quick-Seal

Model: MET-400KOS

Metallics Industries Knock-out Seal 4" 3-Piece Steel Zinc Quick-SealProfessional Electrical Panel Box Sealing SolutionThe Metallics Industries Knock-out Seal 4" delivers exceptional performance and...

Metallics

$65.16

$22.91 Sale
Milbank Steel Hole Seal ANSI 61 Gray with Rubber Gasket and Wing Nut

Model: MIL-A-HS

Milbank Steel Hole Seal ANSI 61 Gray with Rubber Gasket and Wing NutProfessional Enclosure Sealing SolutionThe Milbank Steel Hole Seal provides reliable enclosure protection with ANSI 61 Gray steel...

Milbank

Starting at

$25.63

$22.19 Sale
Milbank Steel Hole Seal with Gasketed Pushbutton Wing Nut - ANSI 61 Gray Enclosure Accessory

Model: MIL-A-HSPB

Milbank Steel Hole Seal with Gasketed Pushbutton Wing Nut - ANSI 61 Gray Enclosure AccessoryProfessional enclosure sealing solution for electrical applicationsThe Milbank Steel Hole Seal provides...

Milbank

$21.64 Sale
SEPCO 539M Steel Conduit Penny, 4-Inch Knockout Closure

Model: SEP-539M

SEPCO 539M Steel Conduit Penny, 4-Inch Knockout ClosureThe SEPCO 539M Steel Conduit Penny is a 4-Inch steel disc engineered to close off and seal unused conduit knockout openings in electrical boxes,...

SEPCO

$12.39 Sale
Steel City Snap-In Blank, Rigid/IMC, Steel

Model: STEEL-BL

1-1/4INCH SNAP-IN BLANK,RGD/IMC,STL

Steel City

Starting at

$81.86 Sale
Steel City Snap-In Blank, Rigid/IMC, Steel, 4/BG

Model: STEEL-BL--11-4BG-1134

1/2 SNAP-IN BLANK,RGD/IMC,STL,4/BG

Steel City

$19.19 Sale
Steel City Snap-In Blank, Rigid/IMC, Steel, EA

Model: STEEL-BL--11

1 1/4 SNAP-IN BLANK,RGD/IMC,STL,EA

Steel City

Starting at

$7.67 Sale
Thomas & Betts DPLG Non-Metallic Duplex Cover Plug, 1/2"

Model: TB-DPLG

Inserts, Elbows & Plugs Certifications UL

Thomas & Betts

$19.29 Sale
Thomas & Betts PLG-RD Zinc Round Plug

Model: TB-PLG

Inserts, Elbows & Plugs

Thomas & Betts

$5.90 Sale
Thomas & Betts Push Penny Knockout Seal

Model: TB-1471-147

1-1/4 PUSH PENNY

Thomas & Betts

$3.86 Sale

Knockout seals for electrical boxes and enclosures - protecting against dust, moisture, and pests in commercial and residential installations. Shop Arlington Industries and Milbank, with fast shipping and expert help on knockout size, material compatibility, and NEC compliance.

Knockout Seals

Metallics Knock-out Seal 1-1/2" 3-Piece Steel Zinc Quick-Seal

Metallics Knock-out Seal 1-1/4" 3-Piece Steel Zinc Quick-Seal

Metallics Knock-out Seal 2" 3-Piece Steel Zinc Quick-Seal

Metallics Knock-out Seal 3-1/2" 3-Piece Steel Zinc Quick-Seal

Metallics Knock-out Seal 3-Piece Steel Zinc 6" x 6" x 1.1"

Metallics Knock-out Seal 4" 3-Piece Steel Zinc Quick-Seal

Milbank Steel Hole Seal ANSI 61 Gray with Rubber Gasket and Wing Nut

Milbank Steel Hole Seal with Gasketed Pushbutton Wing Nut - ANSI 61 Gray Enclosure Accessory

SEPCO 539M Steel Conduit Penny, 4-Inch Knockout Closure

Steel City Snap-In Blank, Rigid/IMC, Steel

Steel City Snap-In Blank, Rigid/IMC, Steel, 4/BG

Steel City Snap-In Blank, Rigid/IMC, Steel, EA

Thomas & Betts DPLG Non-Metallic Duplex Cover Plug, 1/2"

Thomas & Betts PLG-RD Zinc Round Plug

Thomas & Betts Push Penny Knockout Seal