Genuine OEM Jaguar Valve Spring Seat, part number AJ813623. This critical engine component provides a stable and precise resting surface for the valve spring, ensuring correct valve tension and movement within the cylinder head. It is a small, precision-engineered metal part, weighing approximately 0.005 kg. Using a genuine OEM valve spring seat guarantees the exact dimensions and material properties required for optimal valve train function and long-term engine reliability.