Inside each Bola, there is a small xylophone around which a ball moves. The xylophone emits positive waves through a gentle and melodic sound that soothes the baby during pregnancy and relaxes it after birth. The Bola is sold with a waxed cord for tying. The necklace is free of nickel and lead. It is suitable for all occasions, both formal and informal, parties, and baby showers. Thanks to its elegant packaging, it also makes an excellent gift idea. This model can be paired with a separately available chain.