eno ET-31V clip-on tuner is professionally designed for violin family it features violin viola cello double bass and chromatic tuning items auto tuning mode easy for operation bright LCD display and pendulum motion needle for clearly indicating. Super anti-interference high accuracy fast response best choice for your instruments. Features: Automatic tuning mode tuning items including violin viola cello double bass and chromatic. 440Hz A4 frequency A0(27.5HZ)~A6(1760HZ) tuning super anti-interference high accuracy and sensitivity. Auto tuning modes one button for choose tuning items pretty easy for operation. Bright LCD display with red and green backlit pendulum motion needle for clearly indicating it is in tone or out of tone. Clip-on design directly detects vibration from instruments offers it finest vibration sensor. size free 180 degree angle adjustment with silicone pads inside of clip. Powered by 1 * CR2032 battery(not included). Specifications: Brand: eno Model: ET-31V Display: LCD Tuning Mode: Auto Tuning Item: Violin / Viola / Cello / Double Bass / Chromatic Tuning : A0(27.5HZ)~A6(1760HZ) A4 Frequency: 440Hz Supply: 3V(CR2032) Battery(Not Included) Item Weight: 30g / 1.1oz Package Size: 7.5 * 5.0 * 4.5cm / 3.0 * 2.0 * 1.8in Package Weight: 41g / 1.5oz Package List: 1 * Clip Tuner 1 * User Manual(English / Chinese) Note: instrument is not included. battery not included.