We have a few of these lightly-used OEM Subaru/Clarion stereo head units that were removed from customer cars when they had aftermarket head units installed. They are a factory-installed double-DIN unit with AM/FM/satellite radio/HD radio/CD capability. This is one of the last factory head units with good old-fashioned knobs and buttons -- easy to use, even with gloves on! (Sure, touch screens are fine, but there's something to be said for an old-school user interface you can use without taking your eyes off the road.)
This head unit will plug directly into any 2015 WRX/STI with a standard double-DIN 4" high rectangular dash opening, and most other similar-vintage Subaru models (Crosstrek, Outback) as well. It could be fit to older Subarus with an adapter harness, which you might be able to get from a place like Crutchfield. It could also be fit to newer models if you retrofit the older 2015-style bezel and surround. No wiring harnesses are included with the head unit.
What you are getting is a good-condition, gently-used head unit that is guaranteed to work, but after that you are on your own. We are not car audio specialists, and can't help with installation, mounting, or wiring. Other than the guarantee that this item will works on arrival, we make no claims to its suitability to your car or audio setup. If you are not sure what you are doing, consult a car audio specialist BEFORE ordering!
Photos are of one of the units we have; others will be similar but wear details may vary slightly.
Note that satellite radio functions will require an active satellite radio subscription.