An assortment of nylon knock-out seals from The Hillman Group. Nylon knockout seals effectively plug electrical knock-outs. They are molded from 6/6 nylon and are colored gray to resemble galvanized steel. Variants included in this assortment fit punched or drilled holes ranging from 7/8" to 2-1/2" in diameter. Full assortments of #58173 contain six (6) refills comprised of Hillman item numbers #58174 - #58179.