2-pcs per blister card. Throw the metal pair into the air. As they hit up against each other, they make a very realistic rattlesnake sound. Chatter Stones Mystic Magnets are a new innovative toy, Singing Magnets, Magnetic chatter mystic stones that buzz. They are oblong magnetic stones. They are singing magnets that measure 1-3/4" long. Hold them in your hand and toss them in the air just right and you get the fabulous chattering buzz sound. The action is completed by catching them in your hand. They are new and exciting, fit in your pocket, and provide hours of fun as you invent new ways to toss them and make the stones chatter, buzz, and sing. A fun magnetic toy to toss. Singing magnets chatter and buzz. They are bariumferrite which is a definite chemical compound, with the formula BaFe12O19.1-3/4" long