Rayhunter is a project for detecting IMSI catchers, also known as cell-site simulators or stingrays. It was first designed to run on a cheap mobile hotspot called the Orbic RC400L, but thanks to community efforts can support some other devices as well. It's also designed to be as easy to install and use as possible, regardless of your level of technical skills. This guide should provide you all you need to acquire a compatible device, install Rayhunter, and start catching IMSI catchers.