The right protective devices for the most resistant rock cracks. The Ball Nuts were invented in 1987 by John Middendorf and were initially called Lowe Balls. They are the true secret weapon of climbers on self-securing tours. In fact, they are small marvels that are not afraid of the narrowest rock cracks with parallel surfaces where the only alternative would be to hook. Moreover, they are ideal in the pin scars (cracks caused by constant hitting and removing of the hooks) and in the small concavities where even the most modern microcams can do nothing. In short: The most experienced fans of the classic climbing tours should always have a pair of ball grooves (e.g. numbers 2 and 3) with them because of their extreme ease.