Nitrile O-Rings are one of the simplest, yet most engineered, precise and useful seal designs ever developed. This assortment of O-rings features parts measuring 3/16" wide. O-rings in this assortment are made of high-strength Nitrile (Buna-N) rubber. O-rings are ideal for myriad applications. DIY projects, plumbing services, and contracting work are made easier with Hillman O-rings. Full assortments of #56060 contain six (6) refills comprised of Hillman item numbers #56061 - #56066.