Mounting in the bottom of the fuel filter, the sensor detects water in the fuel. Fuel Sensor Part Number: 3808616, 874572. Compatible Models: D3, D4, D6. Replaces Part Numbers: 3808616, 21139810. Compatible with Crude Oil Systems: D3-110I-A, D3-110I-B, D3-110I-C, D3-110I-D, D3-110I-E, D3-130A-A, D3-130A-B, D3-130A-C, D3-130I-A, D3-130I-B, D3-130I-C, D3-140A-D, D3-140A-E, D3-150I-D, D3-150I-E, D3-160A-A, D3-160A-B, D3-160A-C, D3-160I-A, D3-160I-B, D3-160I-C, D3-170A-D, D3-170A-E, D3-170I-D, D3-170I-E, D3-190A-B, D3-190A-C, D3-190I-A, D3-190I-B, D3-190I-C, D3-200A-D, D3-200A-E, D3-200I-D, D3-200I-E, D3-220A-D, D3-220A-E, D3-220I-D, D3-220I-E, D4-180I-B, D4-180I-C, D4-180I-D, D4-180I-E, D4-210A-A, D4-210A-B, D4-210I-A, D4-210I-B, D4-225A-B, D4-225A-C, D4-225A-D, D4-225A-E, D4-225I-B, D4-225I-C, D4-225I-D, D4-225I-E, D4-260A-A, D4-260A-B, D4-260A-C, D4-260A-D, D4-260A-E, D4-260D-B, D4-260D-C, D4-260D-D, D4-260D-E, D4-260I-A, D4-260I-B, D4-260I-C, D4-260I-D, D4-260I-E, D4-300A-A, D4-300A-C, D4-300A-D, D4-300A-E, D4-300D-A, D4-300D-C, D4-300D-D, D4-300D-E, D4-300I-A, D4-300I-C, D4-300I-D, D4-300I-E. Material: Plastic. Color: Black. Package Contents: 1 x Water Sensor. Note: Only the items listed in the package contents are included. Other products are not included. Due to light reflection and differences in display settings, the color of the item in the image may vary slightly from the actual product. Measurement may vary by +/- 1-3 cm.