It's exactly like the one pictured in scortch99th's picture in this thread:
http://www.sr20forum.com/general-sr20/158043-cusco-rear-b13-stb.html
I got it off eBay but never installed it. It's been sitting in my garage for about 7 years, and is still in it's original packaging. Time for me to sh*t or get off the pot.
Frankly, there are better options these days, but for you guys that like rare JDM stuff, here you go. $150 + shipping.