Pure copper. Cost a little more than CCA but gave us a perfect signal on a 300ft line utilizing a powerline adapter and a cheap router only, no needed signal booster or anything like that. Running from apple router, to powerline a, to powerline b, to 300ft cable to cheap router.
Another side note, the cable is a hair less stiff than a cca burial cable just like it, so adding RJ 45s was a little easier