This is a narrowband air fuel gauge, bought originally for $110+.
Face and bezel are silver-metallic.
Price: Was $60, now $55
Generic photo (colours are accurate):
In my car:
Day:
Night:
Good to help ensure your car is not leaning out (potentially causing big-time damage) under boost.
EDIT: All that is needed for it’s installation is some 18-gauge wire. Here are the instructions & wiring/install diagram:
http://www.racerpartswholesale.com/stewarn3a.htm
Thanks for looking!