This 13 mm silicone manifold cap provides a professional solution for sealing unused hose ports in coolant, air, vacuum, and turbo systems. Reinforced high-temperature silicone withstands engine bay heat, pressure, and chemical exposure while maintaining a tight seal. Used by automotive technicians and performance builders, it is ideal for vacuum deletes, boost reference blocking, and coolant reroutes in both temporary diagnostics and permanent engine modifications.