The CMI RopeJack is a mechanical advantage tool for quickly and easily pre-tensioning static lines, light lifting, and cabling. The RopeJack is small and light enough to be carried aloft by a climber, and the length of the handle on the RopeJack limits excessive loading in order to avoid rope damage. The CMI RopeJack is used to remove slack and stretch for lowering and to lift the tips on light limbs without having to break out the big guns. Simply attach both ascenders to your line and crank away to tighten a static line or climb a rope.