Contain a non-toxic, glow-in-the-dark chemical that illuminates once activated. To activate, simply bend the stick until you hear it crack. This will release the chemical from within the stick and it will immediately start to GLOW! NOTE: Each pack contains 12 individually wrapped Turquoise Glow Sticks with an included string necklace. Ordering ONE PIECE means you will only get ONE PIECE from the 12 pack. To receive a full 12 pack, you must order in groups of 12 pieces. Dimensions: Height: 6.0 in. , 15.24 cm. Width: 0.75 in. , 1.9 cm. String Necklace: Approx. 30.0 in. , 76.2 cm. Batteries are not required for this product.