The Boss TU-3W Chromatic Tuner Pedal gives you the power to fine-tune your guitar or bass with absolute precision. This pedal delivers selectable buffered or true-bypass operation with its redesigned circuitry, plus the most transparent audio pass-through possible. So whether you're a pro player who needs to stay in tune under the hottest lights or a beginner just starting, this is the perfect pedal for you. The world s leading stompbox tuner, enhanced with Waza innovation and craftsmanship. Superior tuning and premium signal buffer in one pedal. Tuning functions are identical to the industry-standard TU-3. Refined audio circuitry for exceptionally pure signal pass-through. Buffer can be turned off for true-bypass operation.