Two colors of backlight - Green for 'In-tune' and White for 'Out-of-tune'.Designed to rotate a full 360 degrees for full versatility and range of view. Auto Power Off function - the device will turn off automatically if there is no signal present or operation for 3 minutes. Tuner is bright with plenty of battery life. Battery is a common battery and found on Amazon too! Use it for tuning guitars, basses, violins, violas and ukuleles. Most Overlooked feature is very easy to troubleshoot, C for Chromatic | G for Guitar | B for Bass | V for Violin | U for Ukulele [yes it works for violin and ukulele!!].Designed for beginners and professionals. Battery Included!