The non-invasive retrofit does not change your guitar in any way. The exclusive shelf nut is made from bone for the best tone. Works perfectly with alternate tunings and capos. Tune manually or with any electronic tuner of your choice. It is very convenient to use the Korg DT-7 tuner because it has the Buzz Feiten Tuning System offsets built in. I am able to retrofit either an electric guitar or an electric bass with the Buzz Feiten Tuning System. The cost for the retrofit is $139.00.If your guitar frets are pitted or in need of leveling, those problems will have to be fixed prior to the Retrofit and will incur additional costs. I specialize in guitar set ups which includes leveling and refrets.