Check the listing for details. 5mm Section 219mm Bore FKM Fluoroelastomer Rubber O-Rings. Condition: New. Listed at 140.06 USD. FKM Fluoroelastomer Rubber O Rings: Widely used and the simplest types of seal they are found everywhere from plumbing installations to the space shuttle, they are common in engines and gearboxes, garden hoses, pumps etc. They can be used as face to face seals (like a gasket) or as shaft seals and facilitate both rotary and linear movement. FKM Fluoroelastomer rubber has a particularly wide operating temperature range ranging from - 25 deg Celsius up to + 200 Deg C (higher for short periods) and a high degree of chemical resistance. It is highly suitable for use in engines and other areas where extremes of temperature and chemical exposure are present. Benefits: Excellent sealing properties and durability, wide temp range, high resistance to many chemicals and petroleum based fuels includi.