The FEA-S is the "Swiss Army Knife" of the FEA family. While many other FEAs operate as permanently coupled pairs,the FEA-S is a single-platform wagon, which gives it the flexibility to be used in smaller rakes or fitted with specialized equipment for infrastructure work.

Initially ordered by GB Railfreight (GBRf) and Metronet, they are now widely seen across the UK rail network.