The ASY is a single-action rotary shaft seal for rotating or pivoting shafts with optional protective lip sealing action (ASY) on the side facing away from the medium, against dirt accumulation from the outside. The shorter, thicker, spring-energized sealing lip enables pressure application of up to 10 bar (depending on the rotational speed). The elastomer outer sheath provides good static sealing, good thermal expansion balance, e.g. in light-metal housing, better sealing with greater roughness and secure sealing for split housings as well as good static sealing with thin fluid or gaseous media.