It is pair of strong magnetic hematite olive stone. They are good singer toy and health assistant. Separate them in your hand 1-2 cm and throw them in the air. The strong magnetic attraction of the hematite pulls the zingers together making a whizzing and zinging sound. When you play with them, they are improving your health because of magnetic therapy effect. Perfect toy! We manufacture and supply these size:60*18mm, 45*16mm.If you are interested ,please feel free to mail us.