New! The PT10 "feels" vibrational energy and conveniently tunes without interference from ambient room noise. Small, compact size with large LCD and simulated needle display. Innovative backlight shines red when out of tune and green when in tune. Clamp opens wide for a secure fit on most instruments. Tuning range of 27Hz-1,760Hz (seven octaves), calibration 430Hz-450Hz. Requires one CR2032 3V lithium coin cell battery. Size 2" x 1" x 3.4".