Sharkfin Plectrums ..I've used these plectrums since the mid-1980's here in the US and have never found anything to equal their ability to extract 'bite' and lush harmonic overtones from the strings on my guitars using the rippled edges. Then by simply rolling or flipping it you can provide a smoother, more mellow approach. I challange anyone searching for a unique change in their sound and playing style to add these to your plectrum collection. Get a few with different stiffness/hardness to see which suits you best... Gary Lavengood