O-rings are one of the simplest, yet most engineered, precise and useful seal designs ever developed. O-rings are available in various metric and inch standard sizes. Sizes are specified by the inside diameter and the cross section diameter (thickness). Danco o-rings will repair your leaky faucet and prevent future leaks. Faucets usually have one or more o-rings to prevent water from leaking out around the spout. Danco o-rings are high abrasive resistant and tempature resistant. Danco o-rings will withstand heat between a temperature range of 86 deg. F to 248 deg. F (-30 deg. C to 120 deg. C). These tough and pliable Buna-Nitrile Rubber (NBR) O-Rings will help provide long-term use for your plumbing needs. Danco o-rings are perfect for the everyday DIY'er or the Plumbing Professional.