S-MT12C Breating simulator for Reborn doll,plush toy,heart simulator for baby doll Breathing Simulating Mechanism for Dolls USB --Upload the message. The audios can be played with the motor is moving. These beating hearts are felt more easily than heard and are designed to be the closest sound and feel possible to the human heart. These heart beating come with batteries that are replaceable. Use in our bodies designed for holding beating hearts. No on/off switch or volume control knobs to fuss with, just give your baby a gentle hug and feel the soothing thump of this tiny heart. Hold your ear close to babies chest to hear the soft beating sound. What could be more real...