Brand Name: ACE | Fits For: American Standard | Interior Diameter: 1/2 in. | Material: Plastic | Number in Package: 2 pk | Packaging Type: Pack 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). Ace 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. Replacing worn-out o-rings is an inexpensive alternative to replacing the entire faucet fixture and is an easy DIY installation. Ace o-rings are high abrasive resistant and tempature resistant. Ace o-rings will withstand heat between a temperature range of 86Â °F to 248Â °F (-30Â °C to 120Â °C). These tough and pliable Buna-Nitrile Rubber (NBR) O-Rings will help provide long-term use for your plumbing needs. Ace o-rings are perfect for the everyday DIY'er or the Plumbing Professional. * | Compatible with American Standard Aqua Seal faucets | Stem diaphragm helps stop drips