A rattle! Parametric, easy to adjust the handle size, and the rest of it isn't too hard to figure out.Please exercise due caution if you want to give it to a baby to play. Depending on your print material it may not be baby-safe. Also, it could crack open and release inhalable bits of plastic. Please don't kill babies.Print. Poke something through the holes to snap the peas off inside. Shake!