I have an iPhone 12 Pro Max with battery, screen, and back cover opened.
Face ID is working. The color is blue. The button for volume up/down is detached. If you connect it for repair, it will work.
The phone is clean. It has a screen and battery installed with a 3-month warranty.
I accept trade-ins for 13 Pro Max or 14 Pro Max and I will pay the difference. Negotiable.