DIY Four Hole Panel Base; Dual USB Socket + Voltmeter + 12V Outlet + Toggle Switch.</br>USB socket output: DC 5V / 4.2A; Power outlet: DC 12V; Voltmeter display range: 0 - 24V.</br>Small size and excellent performance.Easy to install?? convenient to use.Widely used for car?? truck?? Rv?? ATV?? boat?? etc.</br>About the switch hole?? It could be used for a cigarette. Can Not be used to light cigarettes.If you don't need the switch for a while. So enjoy it depend on what you wold like it to be. It has two different use?? why not ordering it now</br>Package includes: 1x Cigarette Lighter Socket + 1x Blue LED Voltmeter + 1x Blue Dual USB Charger + 1x Blue