This item is for 4pcs.Material: ferriteColor: blackMeasurement: about 4.5cmX1.5cm/1.77''X0.59''Produce a buzzing or rattling type sound when played with.Great for hand eye coordination， a fantastic stress reliever.A great gift for children and adults.Usage: Place magnets in hand and keep separate with your thumb. Gently toss the toys into the air. The natural magnetic pull will attract them to one another resulting in varying sounds depending on how they are tossed. After some practice you will be able to get impressive high pitched "singing" sounds from these little stones.SKU: 045-495 C