Input Voltage DC is the range of direct-current supply voltage within which a product is designed to operate. Nordic Lights lists this separately from Nominal Voltage DC. A nominal 12 V or 24 V product may accept a wider input range to accommodate normal vehicle-system variation. Operating outside the stated range can cause reduced output, protective shutdown, overheating, or permanent damage. The range does not describe every transient that the product can survive; overvoltage, load-dump, reverse-polarity, and other protections are separate specifications. Wiring and power supplies should be designed for voltage at the lamp under real load conditions.