Please read the following description and profile. I purchased blank nuts for a guitar, but I completely got the wrong size and haven't used them. I wonder what these sizes are used for... I don't know, but if you can use them, please do. The material is cow bone, and the size is as shown in the image. One of them is warped in a bow shape, which is visible to the naked eye (see image 6). Shipped via Yu-Yu Mercari.