Genuine OEM Porsche O-Ring, part number 99970750840. This O-ring is specifically designed to seal the coolant temperature sensor, ensuring accurate engine temperature readings and preventing coolant leaks. Its precise dimensions and material composition are critical for maintaining the integrity of the cooling system. Genuine OEM O-rings are manufactured to exact specifications, guaranteeing a perfect fit and reliable sealing performance, which is crucial for preventing coolant loss and maintaining optimal engine operating temperature.