WOW! What an amazing little instrument this turned out to be for me. It is a 6.3 mm interface, with precision tuning ability for guitar and bass tuning, It has a nice and large display screen for excellent visibility under any lighting situation. It's plug and play. Simply plug in and tune your electric guitar / bass. It is powered by a 9V DC Adapter which is included. This tuner has definitely taken the work out of tuning. Thank you! #MUGIG #RankBoosterReview #Sponsored