The VersaValve stem utilizes a large sturdy base plate that can be fitted on different rims by use of rubber grommets. The large base plate ensures a solid contact with the rim bed and the adaptable grommets guarantee an airtight fit on most rims for mountain road or CX use.Universal fit. One valve for all rim typesReplaceable grommetsKit includes VersaValve stems two types of grommet extra valve cores and RVC tool