Dial and lock in your sound settings with d'addario's easy-to-install loknob. Once in place, simply rotate the aluminum knob to click into the sound you need. For larger 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 accessories and offers a complete line of award-winning accessories including cables, picks, tuners, capos, straps, humidifiers, maintenance tools and more.