The AMPA26CA with 42.1V 28.9V 26V DO-218AB TVS ROHS is a surface mount transil transient voltage suppressor diode manufactured by Polytronics. It's designed to protect sensitive components from high voltage transients, such as those caused by lightning strikes, electrostatic discharge, and other voltage spikes. The device has a peak reverse power dissipation of 425 Watts and a reverse stand-off voltage of 6 to 450 volts, and it features a low clamping voltage, peak power capability, and ESD protection. The TVS is compliant with RoHS Directive 2002/95/EC standards.