Thank you for viewing! This is a protective cover to be used over the chin rest of a violin or viola. 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 size) and violas if they have a Guarneri or Kaufman type chin rest. (Currently not compatible with Fresh type or other shaped chin rests) Outer dimensions are approximately 20cm x 12cm, with a pocket opening of about 10.5cm and a depth of about 4.5cm. The outer side is black with a gray kitten pattern (100% cotton), and the inner side is plain black broadcloth (100% cotton). There is no batting inside, so it is thin and stress-free to attach. ⚠️ 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 elastic on the back. We use very soft mask elastic so it won't scratch 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. You can also thread it through the shoulder rest to save the trouble of attaching and detaching it each 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 hand wash gently when dirty. Ironing is possible except for the elastic and buttons. Images 9 and 10 are the instructions. (A sample was used for the photos.) ⚠️ These will not be included, so please download them if necessary. As a stringed instrument player, I make each one carefully with care and attention to detail, but since these are handmade, please refrain from purchasing if you are overly concerned about minor imperfections. Thank you for your consideration!