The Kaiko Hailstorm is just that awesome it HAD to be made into a wearable tool. At 100grams it is best described as grounding to wear around the neck. The cord is quite long so that it is suitable for any size, however can easily be shortened to your desired length.  

You can 'feather' fingers underneath, shake, tip & wrattle. The sound is sooo satisfying and the 37 moving pins gently 'tickle' the fingers & hand. These are hand crafted, with each pin being individually mounted in the overall casing. It is packed with stimming JOY. Not silent so not great for meetings and the classroom but not so loud that its super annoying either. I would describe it as a soft tinkle, kind of like hail on metal, thus its name.  

They come in one size that will fit all but can easily be shortened to the wearer's preferred length They have a break away clasp for safety if pulled.   Simply cut and retie knot at each end to the desired length & pull knot back into the casing of the clasp.