These are castanets for flamenco, made by DELSUR. They have a black base with red lines. The size is approximately 9 cm in length and 7 cm in width. I used them about once a week for about a year, around 10 years ago. They don't look very worn, and the strings are in good condition. I'm not sure if it was there from the beginning, but there is some slight paint chipping on the black color of the stepped part near the handle. (See the last photo) The bag is not specifically for castanets. I am also selling shoes and a flamenco skirt.