Plastic Knockout Plugs 1/2" - This Plastic Cap plugs knockouts in any enclosure.Plastic Knockout Plugs 1/2" features include: Use this Knockout Hole Plugs to plug unused knockout holes in box or enclosure Trade Size indicated in Chart Indicates Conduit Size For actual OD dimension see Mounting Hole Diameter in chart Dimension Measurements = Inches Order Qty of 100 = 1 Bag of 100 Below is more info on our Plastic Knockout Plugs 1/2"