For preventing metal-to-metal contact between piston and cylinder during sliding (particularly in case of lateral forces), PTFE piston ring is simple assembly and wear-resistant. Thanks for its good media resistance, the piston ring can be used in several media ranging from mineral oil-based hydraulic liquids, environment-friendly hydraulic liquids and water-oil emulsions to flame-resistant hydraulic liquids and dry-running applications. Piston guide rings offer very good gliding behavior, good emergency running properties and also a high wear resistance. Additionally, they help to attenuate mechanical vibrations.