The dual displays come from GMT400 Suburbans, Tahoe's, Escalades, Denali's, and early GMT800s, the later GMT800s started using the one-star mirrors. Hobs does sell kits that comes with the mirror, temp sensor, pigtails, and a wiring cover, I've installed my own, and if you can wire in a radio, the mirror is not a problem at all. Super simple and easy to doAwesome build, just read through and caught up. What are the temperature/compass mirrors originally from? GMT800s?