The combination of the core material and the Teflon encapsulation, ensures a high chemical resistance as well as a resistance to compression sets, meaning it can be used within harsh sealing environments. The encapsulation is seamless, resulting in a product with no weak points. The Teflon offers a higher operational temperature and is FDA approved for applications that must adhere to these regulations. In addition to the solid core, we offer a hollow core FEP, which can be particularly useful when sealing delicate objects such as glass or plastics. Like the O-Rings, the dimensions of an FEP are characterised by the inside diameter (I.D.) and the cross-section (C.S.). We stock many sizes including British standards (BS) sizes, but we can also offer unique sizes that are specific to the requirements of the application in question.