No, Ballnutz are not a punchline to a dirty joke.  They are thin crack protection at its finest, manufactured by Trango.  This specialized type of protection uses a sliding ball/ramp concept to protect parallel sided cracks, pins scars and bombays.  Here at the New, as Micah points out in this video, Ballnutz are a great choice for the common horizontal letter box. Make sure your rack has a variety of pro to keep you secure in a variety of situations--options are a good thing!

So click here to buy your Trango Ballnuts in our shop at Water Stone Outdoors