Pulse Rating Curves are also included on all of the MOV datasheets. They are a series of straight lines indicating to the user how many times a certain event can take place before the MOV has reached the end of its useful life. This graph shows that a high current event that lasts for a certain time interval will end the life of an MOV much faster than a low current event. For example, the top line that is labeled “1” can survive just one hit of high energy and the bottom line labeled “indefinite” can survive indefinitely. This graph helps explain to the user what kind of lifetime to expect when a certain threat is encountered. If the threat is a 3000A secondary lightning strike, lifetime will typically be less than ten hits. But if the threat is a much lower 100A industrial switching incident, then the lifetime extends to thousands of hits.