This Sinister Diesel Coolant Reservoir (Degas) Cap is a top - notch replacement for the factory cap. It fits 2001 - 2016 GM vehicles with LB7, LLY, LBZ, LMM, LML 6.6L Duramax engines and 2017 - 2024 GM vehicles with L5P 6.6L Duramax engines. It functions just like the factory cap but comes with a custom Sinister Diesel look. Crafted from CNC machined, solid billet T6 - 6061 aluminum, it has an interior pressure relief system, ensuring it works even if the gasket fails. The cap is anodized in Sinister Blue or available in Gray, and it's etched with the Sinister Diesel logo. Rated for 15 PSI, it offers a 1 - year warranty, making it a reliable choice to replace failure - prone factory caps.

Using this coolant reservoir cap is easy. Just remove the old factory cap and replace it with this Sinister Diesel cap. Make sure it's properly tightened. As for maintenance, there's not much to do. But it's a good idea to check the cap periodically for any signs of damage or wear. If you notice any issues, you can take advantage of the 1 - year warranty. Also, keep in mind that this cap is rated for 15 PSI, so don't exceed this pressure to ensure its optimal performance. When storing the cap, keep it in a dry place to prevent corrosion. That's all you need to know to get the most out of your new coolant reservoir cap.