The fuel cap is an integral part of the on-board diagnostic and emission control system. It prevents fuel leakage from the filler neck, a major source of hydrocarbon emissions, and plays an important role in preventing fuel flow. Studies have shown that a faulty or missing tank cap can allow up to 114lt of fuel to evaporate into the atmosphere each year.

Farma tank caps are designed and manufactured to prevent fuel loss primarily through evaporation. The caps are designed to lock to prevent fuel theft and vandalism. Opening and closing is easy.