Silver stainless steel construction</br></br>Input Voltage: DC 12V</br></br>Measurement: 0~13000RPM</br></br> Size: 60mm x 56mm (2-3/8" x 2-3/16")</br></br> Mirror Diameter: 57mm(2-5/8"); Outer Diameter: 68mm(2-5/8")</br></br></br>Wire connection:</br></br> Two long wires for lamp: long red – positive, long black – negative. </br></br> Three short wires: short green – ground, short black – power/ignition lock positive, yellow/black – engine signal (some models need to attach high voltage signal line)