1. Material: plastic, elastic sponge 2. Weight: about 96 grams/piece 3. Size: diameter of about 7 cm/piece 4. Applicable age: over 3 years old 5. Applicable people: unlimited 6. Features: flick at will to rotate 360 degrees, press the ball to match colors, puzzle decompression, fine polishing, smooth and burr-free, strong and anti-drop, durable and playful