I use a kernmantel rope with a backsplice around a steel thimble. I attach the anchor with a screw link. I started using a chain anchor after losing a couple of lead pyramids on the Yakima. The chain has less of a tendency to wedge itself between the rocks. The anchor itself consists of several sets (about 35 or 40 pounds) of tire chains looped onto an eye bolt with a large washer and locknut to keep them there.