V321DB40 - 

The DA and DB Series transient surge suppressors are heavy-duty industrial Metal-Oxide Varistors (MOVs) designed to provide surge protection for motor controls and power supplies used in oil drilling, mining, and transportation equipment. These UL recognized varistors have identical ratings and specifications but differ in case construction to provide flexibility in equipment designs. DA Series devices feature rigid terminals to ensure secure wire contacts. Both the DA and DB Series feature improved creep and strike distance capability to minimize breakdown along the package surface design that provides complete electrical isolation of the disc subassembly.
Features:

Recognized as “Transient Voltage Surge Suppressors”, UL File #E75961 to Standard 1449

Wide Operating Voltage Range V_MACRMS: 150 V to 575 V