These babies are an alternative to carrying tiny little cams and can be used where the shape of the notch or crack isn’t giving you enough purchase with a nut.
The Trango BallNutz look like a cam and a nut had a love child, they are active protection but have a very low profile like nuts. Again similar to cams you have a trigger mechanism that rotates a ball within the nut mechanism securing it in the location. These a suitable for shallow cracks or bottle necks and can make an excellent addition to any rack. The will compliment your existing selection of nuts giving you the option to secure cracks that give no purchase, they also add to your cams letting you step down below your traditional cam size.
Again, these are great as an addition to your rack to give you more options when you are climbing. A halfway between cams and nuts, for more info and some instructional videos on their application visit trango.