This is a nifty little alarm with a motion sensor that plugs into your 12v plug in your vehicle or camper. Works perfectly in my Airstream pointing towards the front door while being used as an intruder alarm.
Technaxx Car Alarm TX-100 – https://amzn.to/31Elo1T
12V Cigarette Outlet to USB Converter – https://amzn.to/31EkmD3