Page 624 - Bob Holtzman "The Field Guide to Knots How to Identify.."

86. Klemheist Knot

The Klemheist Knot is known as a “Prusiking knot,” because it slides and

grips like a Prusik (opposite). It works well with a sling that is made of rope
at least half the diameter of the main rope, or with tubular tape, and is said
to be more secure than a Prusik Knot.

Instructions

1. Make a bight in the sling and pass it behind the main rope.

620