These D series relay modules are designed for universal usage in a range of industrial applications. Series-connected contacts, built-in blow magnets and low-wear contacts suppress arcing that can occur from load currents exceeding 100 mA. Options for the 100% function-tested modules include a test button with colored control voltage marking (the ac coil is red and the dc coil is blue) and mechanical switch position indicator. Bright status LED lights indicate the ac coil in red and the dc coil in green.