This Fender clip-on chromatic tuner is a 12 note full range chromatic tuner with dual rotating hinges. It attaches directly to all string, wind, and brass instruments. The detection range is from A0-C8 (27.5 Hz - 4186 Hz). It picks up vibrations using a vibration sensor rather than using a built-in mic to detect the tone. These are always less susceptible to interference from noisy environments than other tuner types. These are extremely accurate and has a bright LCD sweep for easy viewing in any environment. Uses one CR2032 3 volt lithium battery which is included. A4 calibration is A440. Overall size of the tune head is 1 1/2" x 1 1/2". The display rotates making this easy to read when clipped to your instrument. This is a very good, feature-packed tuner at a very reasonable price. Instruction manual is included.