The Bristle Whistle an instrument that lets the Tooth Fairy know when a baby tooth has fallen out. When a child plays the whistle, the melody makes it to Fairyland, and the fairy's wand starts to glow! They put the tooth in the whistle and hang it on their door. The Tooth Fairy will come looking for it once they fall asleep! She takes the tooth back to Fairyland, avoiding the tooth-searching struggle! No more waking up siblings, dealing with squeaky doors, or sticking her hand through impossible bed rails! Say hello to hassle-free tooth collecting!