Surges in voltages arise from places like ESD (electrostatic discharge), moving charged conductive objects or is part of the circuit application. ESD strikes can come from human interaction such as a person touching buttons on a keypad. Moving charged conductive objects are found in electronics such as industrial equipment; an automatic metallic sliding door is one example. Some applications like a mobile phone flash require anti-surge protection; the circuit for this application is shown here on the bottom right. If not properly protected, these surges will degrade the life and performance of electronic components. The components can experience catastrophic failures where the device no longer functions, parametric degradation where a parameter such as resistance shifts out of specification, or latent damage where the device appears to function properly but the lifetime is dramatically reduced.