The Hendrickson S-39932-1 is a genuine Hendrickson fill port plug for heavy-duty truck suspension systems. Part number S-39932-1 is also referenced as S399321. This plug services the fill port on Hendrickson suspension assemblies, keeping the lubricant or fluid sealed at the designated service point. If you need to verify this part fits your specific suspension model or axle configuration, call Pro Gear and Transmission and we can help you confirm the correct application before you order.FeaturesGenuine Hendrickson suspension componentFill port plug for Hendrickson suspension assembliesPart number S-39932-1, also listed as S399321Direct-fit service replacement for the suspension fill portSold by Pro Gear and Transmission