Just found this on the site. It says one pair are include. Get two pair.
Includes:
pair of billet 4340 precision CNC machined steel R230 CV/Companion flange adaptors, heat treated, cryogenically treated, and double tempered!
one pair of precision CNC machined end stops, required to ensure appropriate CV travel
high grade hardware for mounting brackets, this includes OEM 280ZXT stub axle nuts which are preferred (no peening required) and all other high grade hardware for the install
optional choice below: custom high strength male male splined axles, engineered with this package