Flamenco castanets bolero fibre nº 4 – 3 soundboxes, made of artificial fibre and the chemist adds a part of cellulose to improve their sound and their durability. The castanets are black and their tone is matt. Their “neck” is slender and their “ears” are long to rest the fingers. The inside part of the castanets have been hollowed in their two interior faces to get the greatest sound and reduce the weight. Case is included.