Korg Clip On Chromatic Tuner Green - Korg AW-2G-GR Clip-on chromatic tuner mounts directly to any guitar headstock - even when tapered Double ball-joint mounting places display at an easy-to-see angle Backlit display with reversible metering assures high visibility in any condition Wide range (A0 - C8) chromatic metering is accurate to +/- 1 cent Energy saving "Auto" mode extends battery life