4 in 1 marine car charger socket panel, 12v 4.2a dual usb charger socket power outlet & led voltmeter & cigarette lighter socket & led on off rocker toggle switch for car marine boat rv truck linkhood <b> noted: wire diagram not including </b><br> there are + & - on each module except the three-prong switch. one prong is brass, the others are silver. <br> about this 3-prong switch, the brass prong is negative and the center is positive in, the outer silver prong is supplied positive. <br> <br> <b> specification: </b><br> style: 4 in 1 charger socket panel <br> color: black shell & blue led light <br> material: abs <br> usb output: dc 5v/2.1a&2.1a (total 4.2a) <br> power outlet: dc 12v <br> voltmeter display range: 6 - 24v <br> toggle switch: 20a 12v dc <br> package weight: 135g / 4.8oz <br> cigarette socket dimension: approx. 1.18" * 2.13"(30mm * 54mm) <br> usb car socket dimension: approx. 1.18" * 2.05"(30mm * 52mm) <br> rocker toggle switch: approx. 1.18" * 1.57"(30mm * 40mm) <br> led voltmeter dimension: approx. 1.18" * 1.02"(30mm * 26mm) <br> four holes panel dimension: approx. 4.13" * 3.42" (l * w) <br> <br> <b> package included: </b><br> 1 * four hole panel base <br> 1 * dual usb socket <br> 1 * led voltmeter <br> 1 * 12v power outlet <br> 1 * on-off toggle switch <br> 4 * mounting screws <br> 9 * insulated terminals <br>