CURVED NUT (ACOUSTIC AND ELECTRICAL) Planet Waves NS Capo Tri-Action Capo. The NS Capo Tri-Action ensures hum-free intonation at any fret. Tri-Action geometry reduces the force required to open and close the bonnet and uniform tension is applied regardless of mast profile. Combined with the micrometric adjustment of tension and direct horizontal pressure, the NS Capo Tri-Action virtually eliminates the need for re-tuning during use. Also, its lightweight composite construction adds virtually no weight to the instrument's neck. For 6-string acoustic and electric guitars with rounded fingerboards. Includes plectrum holder.