This tubeless sealant injector from Park Tool is designed to make adding or refreshing sealant cleaner and more controlled. Its syringe-style body and hose assembly allow sealant to be delivered directly through the valve stem—whether the valve core is removed or left in place—helping prevent spills and reduce mess during setup or maintenance. The capacity is sized for typical mountain, gravel, and road tire volumes, making it a practical tool for routine tubeless servicing.