The Original Gas-O-Matic® is a mechanical wind-up fart toy with an amazing repertoire of fart sounds sure to turn heads and disgust innocent bystanders! No batteries necessary. Simply wind the center spinning device (aka the "Sphincter") of the Original Gas-O-Matic®, hide it under your leg, then give that umistakeable "fart lean" and "rip it". The Original Gas-O-Matic® is proudly made in the USA using safe, high quality and durable materials for long lasting fun!