A cleverly simple blocking knot. It is used at the focal point of an anchor, using a Supplemental Anchor System (SAS). The CRT HauLine works well in this application.
With the ends of your SAS connected to the anchor points, pass the focal point loop through the top of a screwgate carabiner. Wrap the loop around the two strands above the carabiner enough times to adjust the desired position of the carabiner. Finish by clipping the loop into the carabiner.