SCS
Single, spring-loaded lip. This is the most common design used when primary function is either exclusion or retention.
SCSL
Single, spring-loaded lip. Adjustable or fixed spacing buttons on back of seal. Used to set the gap between seals, when used in pairs, allowing lubricant to reach both sealing lips.
SCSO
Single, springless lip. Used when axial/radial space restrictions prevent the use of a SGS seal. Also used as a shaft wiper.
SCSK
Single, spring-loaded lip. A garter spring is retained by a flat, leaf-spring closure. Used in applications that must exclude the possibility of spring separation.