Box says fits Shelby Lancer and Shelby CSX.  (I'm guessing only 1987 CSX...not 89 CSX, but I'm not 100% sure on that.   Part number on box is:  C3940344.
 
Inside the box are both LH and RH pieces.  So it is indeed the pair of them.
 
Very nice, extremely hard to come by, factory OE Shelby/Mopar parts.  These are what are located inside the rear hubs on your Shelby/Dodge.  They allow you to make adjustments to your E-brake so it doesn't drag (i.e.  so you can make it not too tight, or not too loose).
 
You will receive the pair as shown (Left and Right  hand side)