Page 35 - D. Raleigh "Knots and ropes for climbers"

Klemheist.

Klemheist

When you wrap a loop of cord around the rope, you get the Klemheist. This variation on the Prusik
works similarly but is easier to slide up the rope and thus is the preferred knot for lengthy ascents. Add
more wraps to generate more friction, as you do with the Prusik. Unlike the Prusik, the Klemheist grips
best when you load it straight down. When you have a diagonal or horizontal rope to cross, the Prusik
is the safer knot. You can tie a Klemheist in webbing as well as cord, but webbing generally doesn't
grip as well.

Common Use
Ascending single and double rope