The 1.5KE400A with 548V 380V 342V DO-201 TVS (Transient Voltage Suppressor) ROHS (Restriction of Hazardous Substances) manufactured by DOWO is a bilaterally symmetrical, high-performance, unidirectional, surge protective device designed to protect voltage sensitive components from damage due to transient surges. This device is designed to protect against spikes of up to 548V, 380V, and 342V, and is compliant with the European Union's RoHS regulations. It is a standard DO-201 package, meaning its dimensions are approximately 6.3 x 3.2 mm, and is suitable for surface mounting.