These colorful sticky balls can help relieve your anxiety and bring fun. When you encounter any situation that makes you depressed, just throw these balls to the ceiling. And these balls are orescent design, will glow in the dark after absorbing some light. Specifications: Material: TPR + Silicone Quty: 4Pcs, 8Pcs (optional) Item Diameter: 45mm / 1.77in Package Weight: 4Pcs: 48g / 1.69ounces 8Pcs: 96g / 3.39ounces Package Size: 4Pcs: 100 * 100 * 50mm / 3.94 * 3.94 * 1.97in 8Pcs: 150 * 100 * 50mm / 5.91 * 3.94 * 1.97in Note: When you receive these balls, do not throw them directly onto the roof as they are very sticky. First, please play it around your hands for a while, then you can throw it on the ceiling. It's going to go down for a while. Packing List: 4 * Stick Wall Balls