EWK Water Sensor Wrench for 6.6L Duramax Diesel Engines 2001-2011 1. Plastic sensor has a 12 sided design that is easily damaged by tools, like pliers, that do not specifically fit the sensor. 2. Use when replacing the fuel filter or when servicing the water sensor. 3. Application Model / Year : 2001-2011 6.6L Duramax diesel engines.