Keep your electrical boxes safe, compliant, and securely sealed with the nVent GARDNER BENDER KO708 3-Inch Metal Knockout Seal. Engineered as a premium solution for closing off exposed or unused openings, these metal knockout seals are fast and easy to install from either the inside or outside of the box. Whether you are a professional electrician handling heavy-duty commercial projects or a DIY enthusiast upgrading home hardware, this seal provides a clean, reliable, and code-compliant finish. Crafted for rugged longevity, the seal is made of rust-proofed, cold-rolled galvanized steel. The heavy-duty 16-gauge steel construction ensures maximum rigidity and defense against impacts, while the matching screw and bar are zinc-plated to resist corrosion and breakdown. Featuring a 3/8-in. thread, the hardware creates a tight grip across the knockout hole. No complex tools or multi-step procedures are needed for setup—one screw holds seal in place perfectly, pulling the backing bar tight against the box structure to form a rigid closure. Accuracy on the job site is critical, which is why this knockout cover is distinctly marked for size and catalog number for easy installation and quick identification in your toolbox or inventory. The face of the disc is uniquely embossed for quick self-centering in unused knockouts, completely eliminating guesswork and keeping the seal perfectly aligned over the opening as you tighten down the hardware. Trust nVent GARDNER BENDER to deliver the specialized durability and smart design required for your next electrical configuration.

• SELF-CENTERING DESIGN - Embossed for quick self-centering in unused knockouts, this metal knockout seal ensures a precise and reliable fit every time to safely secure open exposures in electrical boxes.
• EASY INSTALLATION - Fast and simple to mount from either the inside or outside of the box, where just one screw holds seal in place securely to drastically reduce your installation time and effort.
• PREMIUM GALVANIZED STEEL - Made of rust-proofed, cold-rolled galvanized 16-gauge steel to deliver long-lasting durability, structural integrity, and exceptional resistance against corrosion over time.
• ZINC-PLATED HARDWARE - The included assembly screw and bar are zinc-plated for enhanced heavy-duty protection, ensuring the clamping mechanism remains secure and marked for size and catalog number for easy installation.
• PACKAGING NOTICE – This product may arrive with packaging labeled Gardner Bender as branding transitions to nVent GARDNER BENDER. Product design, specifications, and quality remain unchanged during this rollout.
• 16-gauge steel; 3/8" thread