10 PCS Electrical Box Knockout Plugs Round Stainless Steel Seal Electrical Panel Knockout Plugs for Closure Unused Electric Box 17 mm Outlet Holes

Material: Made of stainless steel | Size: Outside diameter: 21 mm / 0.827 inch; Inner diameter: 10 mm / 0.39 inch | Easy to use: No tools are required, just press the electrical panel knockout cover into the hole with your fingers | Application: Suitable for holes with a diameter of 17 mm / 0.67 inch | Package includes: 10 * Seal Electrical Box Knockout Plugs