The Sinister Diesel Billet Fuel Plug/Cap for the 2003-2007 Powerstroke is a stylish and durable option to keep dirt and moisture from entering your fuel tank. The factory uses a small, flimsy plastic plug and the Sinister Diesel Fuel Plug is CNC Machined from solid billet aluminum and utilized a tight O-ring seal. It's laser etched with our Sinister Diesel logo and anodized in Limited Edition Sinister Green. Features: Anodized in Limited Edition Sinister Green CNC Machined from T6-6061 billet aluminum Laser etched Sinister Diesel Logo O-ring for a tight water/debris resistant seal Installed magnet in base for storage while fueling Includes: (1) Sinister Diesel Billet Fuel Plug/Cap (1) Viton O-ring