Smiths ammeter gauge, likely from a classic car, used to measure the flow of electrical current in amperes (amps). Function: Measures the charging and discharging of the battery. A positive reading indicates the battery is charging, while a negative reading indicates it is discharging. Brand: Smiths is a classic British instrument manufacturer known for its automotive gauges. Range: The gauge in the image measures from -35 to +35 amps. Size: Typically, these gauges are 52mm (2 1/16 inches) in diameter. Installation: Requires a 52mm mounting hole and connections to the vehicle's Untested
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