This diesel exhaust fluid (DEF) filler cap is designed to match the fit and function of the original cap on specified vehicles, and is engineered for durability and reliable performance. This part is compatible with the following vehicles. Before purchasing, enter your vehicle trim in the garage tool to confirm fitment. [Freightliner Cascadia: 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020]