Camp Ball Nuts are small, very strong and easy to use.
A hybrid form of passive-active protection, Ball Nuts are designed to be placed in super thin cracks, 3-18mm, where virtually nothing else can be placed.
Ball Nuts consist of a protruding half-sphere, the “ball”, that rests in a track of a nut. Like a camming device, you pull the trigger to place it, bringing the ball down a widening track into which it recedes, and putting the device into its narrowest configuration. When the trigger is released, the ball moves upward, wanting to expand back out, thereby camming against the rock.
Downward force, as in the case of a fall, exaggerates the camming action as the ball tends to expand even further. Its just the protection you need when climbing thin cracks.