Let your creativity fly with our trilogy multiple tuning bridge designed for dobro. Attaches at the strap button. Easy installation. Here's how it works...... The Trilogy provides you with instant, smooth, and precise retuning of each string to three player-preset notes by means of specifically designed cam levers. Each string is independent of adjacent strings. (Tuning ranges of the 6th and 5th strings are approximately an octave; the 4th and 3rd strings are over a fifth; the 2nd string is approximately a fourth; and the 1st string is over a minor third.)