There are three typical levels: Lightning arrestors. Big and mean, usually found in large facilities located in high-risk areas. Takes an extremely high voltage and clamps it down. Surge Protective Devices (SPD or TVSS). Mounted on your panel board or load centre; sometimes larger UPS models may have some level of this, but typically not a great amount. Clamps voltage down two even lower tolerances (~1 kV or less). Local outlet level surge protector. A simple surge strip; small plug-and-play UPSs often have this as well. Brings voltage down to levels that will not permanently damage connected equipment (typically ~380V). Lightning strikes have such an incredible amount of energy that only an expensive lightning arrestor would protect you from a direct hit and they often don't guarantee complete protection. For the best protection against lightning strikes, you want to develop a two-stage defense with something at your panel and something at the outlet level. Visit the Surge Protection Devices page for some informative videos and additional information.