It can apply or travel, for musicians or teachers or science lovers Provide clear tone, sound and accurate tuningTake from a tuning fork "standard form" is one of the important links in the piano tuning process. Its significance lies in the relationship between the sound of the piano and the position of the pitch. Tone Temperament Order:Specify the standard voiceThe standard pronunciation of the tone of the reference key coming from each groupIn the reference tone set as the standard key tone, it is output for each remaining key toneTone reference tone keys, each key tests the rest of the pitchAbsolute standard tuning fork A-440Hz, sound detection performance. The soft stiffened case can better protect it from wear and tear. Material: Steel Size: 4.88*0.79*0.39 inches Weight: 1.17 ounces Color: Silver Package Contents: 1 * Tuning Fork1 * BagOnly the above package content, other products are not included. Note: The light and different displays may cause the color of the item in the picture to be slightly different from the real thing. The allowed measurement error is +/- 1-3cm.