The Loc-Sure for the 2015 Golf & Golf Sportwagen TDI is a vented, screw-in, locking billet cap for the diesel filler neck. The Loc-Sure offers protection from fuel thieves and from malicious people who would contaminate your fuel. The Loc-Sure utilizes the parent company's Secure Screw system which has been tested and approved by military and other secure facilities as a low-level human secure system. The Loc-Sure features a 2.5" diameter top face with scallops and knurling for good gripping. The U-Cup seal contacts both the inside and the outside diameter of the fuel filler rim to ensure a proper seal. Each Loc-Sure purchase comes with the Loc-Sure cap and one fully machined stainless steel Pocket Secure Key with complimentary stainless steel key ring. Additional keys can be purchased using the information from our Keys page. BEM Auto's Loc-Sure body is fully machined from aluminum bars at the BEM Auto factory and is finished in a generic green anodized surface, etched to identify the assembled unit as a diesel only cap. The Secure Screw is manufactured from 18-8 stainless steel to provide good corrosion resistance.