This is the chassis mounted filter that separates water and particulate out of diesel fuel before it reaches the engine mounted filter. On a common rail system the injection hardware is unforgiving of water and debris, so this filter is doing real protective work and is worth changing on schedule rather than when it starts to complain. Note that Ram diesels use two filters and this is only one of them.

Mopar Accessories 68436631AA Fuel and Water Separator Filter Features:

• Fuel and water separator, chassis mounted location.
• Two micron high efficiency multi layer depth media.
• Fits 2019-2024 Ram 2500, 3500, 4500 and 5500 with the 6.7L Cummins.
• Fits 2020-2023 Ram 1500 with the 3.0L EcoDiesel, plus Jeep Wrangler and Gladiator EcoDiesel.
• Confirm which of the two filter locations you are servicing before ordering.