Knitted wire mesh is increasingly used as a Porous Transport Layer (PTL) in alkaline and PEM electrolyzers for green hydrogen production. Acting like a precision spring, it distributes clamping forces evenly and maintains catalyst contact, while its open structure allows efficient gas-electrolyte flow. A DLR study found this can boost current density by 33% and cut cell voltage by 74 mV at 2 A/cm² - improving efficiency and lowering energy costs.