The Sinister Diesel DEF cap for the 2011+ Powerstroke is a stylish and durable alternative to the stock Diesel Exhaust Fluid cap. The cap is CNC machined from solid billet T6-6061 aluminum, and finished in our signature Sinister Blue. Features: Anodized in Sinister Blue CNC Machined from T6-6061 Billet Aluminum Direct replacement for factory cap Laser eteched Sinister Diesel Logo Includes: (1) Sinister Diesel DEF Cap (1) O-Ring