The SA20A with 32.4V, 22.2V, 20V plugin TVS ROHS is a surge arrester manufactured by Yageo. It is a small-sized component designed to protect vulnerable electronic circuits from surge overvoltage spikes. It works by clamping the overvoltage spike voltage and then dissipating the energy through its internal resistor. The SA20A is also RoHS (Restriction of Hazardous Substances) compliant, meaning it meets environmental regulations designed to reduce hazardous waste and protect public health.