Black footed limpets have been collected by myself in small batches from beaches in Cornwall. I always check no one is home before I take a shell then carefully drill them and they are strung onto hand plaited silk thread. 

Surgical stainless steel findings. Highest quality stainless steel does not rust or tarnish, a hard wearing metal with a finish like antique sterling. Also suitable for people with metal allergies, stainless steel is used predominantly in the medical profession as people are less likely to react to it.

Length is 20 inches, see me wearing for size :-)