D'Addario LokNob Large - Black/SilverDial and lock in your sound settings with DAddarios easy to install Loknob. Once in place, simply rotate the knob to click into the sound you need. For larger sound adjustments, simply lift the knob, rotate to your desired sound, then release. Loknob retrofits to most amplifiers, effects pedals, instruments, and live studio gear and is available in two sizes and a variety of colors. D'Addario is known for innovative, problem solving, quality musical