Our specially designed 1.5" NPT Adapter is a must-have when installing a Smart Oil Gauge on an oil tank with a non-standard fitting. NOTE: An off-the-shelf plumbing adapter will cause interference with the sensor and WILL NOT WORK. Our adapter features an internal guide cone which aids the sound wave from the sensor in reaching the oil without any interference – a feature not found in off-the-shelf reducers. This design guarantees that the Smart Oil Gauge delivers precise and consistent readings of your oil levels. Determining if this adapter is right for your tank is straightforward. Most tanks will not require this adapter, as they typically have standard 2" NPT openings. However, if your tank's fitting measures approximately 1.9" across, this 1.5" NPT adapter is the perfect solution. Note that this adapter is not needed for fittings measuring 2.375" across, nor is it suitable for Roth Double-Wall Tanks or tanks with 1.25" fittings. Installation is simple, ensuring that your Smart Oil Gauge is up and running in no time, providing you peace of mind with accurate and interference-free readings of your heating oil levels. Choose our 1.5" NPT Adapter for a seamless and efficient upgrade to your heating oil tank setup.