ROPE GRAB A rope grab operates the same as a cable grab for fall arrest protection but is specifically designed for use on rope only. This unit moves freely up a rope while climbing, but will lock into place if a fall or slip occurs. This is specifically designed to be used with 10.5 - 12mm. (1/2 in.) kernmantle rope. The rope grab is made of stainless steel and features a cam lever that has two ridges for high speed activation. The ridges give way to the pressure plate of the cam lever, which brakes against the rope in a low arresting force that causes minimum damage to the lifeline. Do not use on manila, cotton, or any type of natural rope.