Theguitar mate is a mini portable guitar tuner which is very easy to use and operate by vibration which provides the user with accurate tuning. Description: Brand new and high qualityCompact design and let you take it anywhereWorks by vibration, accurate tuning despite ambient noiseEasy-to-read LED indicator tell you which way to tuneTune to standard guitar tuning of B,E,A,D,G,B,EIt also has a flat option for Bb,Eb,Ab,Db,Gb,Bb,EbEasy operation with one control switchesTurnable 180 degree for easy viewing, chip on design440 Hz A4 freauencyPowered by one CR2032 cell batteryAuto-off save your battery if no input is detected for 3 minutes Package Includes:One guitar tunerOne user manualOne CR 2032 cell battery