The 1.5KE51A with a TVS ROHS manufactured by Yageo is a unidirectional Transient Voltage Suppressor (TVS) diode. This DO-201 diode protects against ESD, electrical fast transients, and other transient voltages, and has Max. Reverse Stand-Off Voltages of 70.1V, 48.5V, and 43.6V. The diode is also RoHS compliant and lead-free.