This white paper provides guidance on selecting Surge Protective Devices (SPDs) to protect electronic systems from voltage spikes and transient surges. It outlines the importance of SPDs in safeguarding electrical circuits and communication lines from disruptions caused by lightning, power outages, and other events. The document details the operational basics of SPDs, including their installation at service entrances and specific equipment locations. It presents a step-by-step approach for designers to choose the appropriate SPD, emphasizing the evaluation of safety and compliance standards, types of SPDs, and electrical specifications. Additionally, it discusses the significance of analyzing SPD features, maintenance ease, and consulting with professionals for complex installations. The paper concludes by reinforcing the necessity of selecting the right SPD to ensure the safety and longevity of electrical systems.