Description de chez Amazon USA : - The purpose of the Mini "Spider" is to Capo each string individually making possible hundreds of tunings without de-tuning your instrument - The Mini Spider Capo is for narrow necked instruments. These include, but are not limited to: Banjo, Ukulele, Mandolin and Bouzuki - Fingerboard width: 29 51mm - Users report that because the Spider Capo clamps over the fingerboard, and not behind, it can also be used on the Mountain Dulcimer - As banjo players in particular like to tune in different ways to start with, Spider Capo will multiply each tuning by the same factor making hundreds and hundreds of tunings available