Fibo houses four metal pearls which rotate, tap or press on the wearer’s skin, emulating the movements of the baby in real time. These four pearls are four different sizes because the baby has different movements with different strengths throughout the day. If your baby has the hiccups, then the little pearl will gently tap against the wearer’s wrist, or if the baby is rocking out to music and is kicking mama at a good rate, then the medium pearl will push against the wearer’s skin. Since the skin at the pressure point on your wrist is a sensitive area, we chose to design Fibo to press against this area, so you can feel the subtle movements throughout the day.