The Ernie Ball Power Peg Pro USB-C features a universal head for most acoustic, bass, and electric guitar tuning machines. It offers superior torque and is compatible with all tension requirements, from mandolins to ukuleles to vintage basses. The Power Peg Pro restrings your instrument up to 80% quicker than manual peg winders, plus the rechargeable lithium-ion battery and fast-charging USB-C power cable (included) make purchasing batteries a thing of the past.