Thank you for viewing! This is a protective cover to be used on the chin rest of violins and violas. It protects your precious instrument from dirt and sweat, and is made at the request of those with allergies to metal or varnish, or those with sensitive skin. This cover can be used for both violins (4/4) and violas if they have a Guarneri or Kaufman type chin rest. (Currently not compatible with Fresca type or other shaped chin rests) Outer dimensions are approximately 20cm x 12cm, the pocket opening is about 10cm, and the depth is about 4cm. Both the front and back are made of soft, navy blue twill fabric (100% cotton). There is no batting inside, so it is thin and stress-free to wear. ⚠️ The colors in the photos may not be exactly as they appear due to smartphone photography. Please understand that the color of the actual product may differ slightly from the photos. Cover the chin rest with the pocket part and secure it with the rubber band on the back. We use very soft mask elastic so it won't damage your precious instrument. It shouldn't affect the sound, but if you are concerned, you can put it over the shoulder rest or wrap it around the shoulder rest. Also, if you put it through the shoulder rest, you can save the trouble of attaching and detaching it every time. The length of the elastic can also be finely adjusted with the stopper. This stopper is also made of silicone, so it will not affect the instrument or the sound. The button is made of acrylic, but the back button that touches the instrument is made of soft felt fabric. Please wash gently by hand when dirty. Ironing is possible except for the elastic and buttons. Images 9 and 10 are the instructions. (A sample was used for the photo) ⚠️ These will not be included, so please save them by screenshotting if necessary. As a stringed instrument player, I make each one carefully with dedication and care, but since they are handmade, please refrain from purchasing if you are overly concerned about details. Thank you very much!