For the slim and grim. Invented in 1987 by John Middendorf and originally brought toåÊmarket as Lowe Balls, these have become the secret weapon of many aid and tradåÊclimbers. These little wonders will work in small parallel-sided cracks where the onlyåÊother option is pounding a piton. Ball Nuts also work in pin scars and small flares whereåÊeven modern micro cams simply won‰۪t fit. Since they weigh so little, many advanced tradåÊclimbers keep a #2 and #3 on their rack at all times.