This high-quality kit contains two EL288 rear hub end caps that are ideal for replacing the old ones on your FSA/ Vision Metron rear wheels. Genuine Vision spare part. Vision products were launched nearly 20 years ago at the Kona Iron Man. Since then they have earned the reputation of being amongst the fastest & most aerodynamic components in the professional field. Vision components are designed using Computational Fluid Dynamics (CFD) software & verified through extensive wind tunnel testing, then proven under its sponsored professional athletes to guarantee you the highest performance.