The Pro Capo in silver is made from aircraft grade aluminum for use on acoustic and electric 6 and 12 string guitars. The Pro Capo assures buzz-free in tune performance at any fret. A patented micrometer adjustment mechanism allows the player to dial in the exact tension needed for clear ringing notes without excessive force in any position on the neck. This greatly reduces the need to retune your guitar during and after capo use. The sleek construction can withstand the toughest playing or touring schedule while adding very little additional weight or obstruction to the instrument. The D'Addario Series of capos are the result of an ongoing collaboration between famed product designer Ned Steinberger, Jim D'Addario and D'Addario., Designed for acoustic and electric guitars with radiused fretboards, Micrometer tension adjustment assures buzz-free in tune performance at every fret, Single hand operation, Aircraft grade aluminum construction, Works for 6 or 12 string acoustic and electric guitars; also available in a classical guitar version