Description It is a scientific experimentenergy bar, it can exercise your children practical ability, train your children observation capability, thinking and analytical skills. Colored light will appeal to children and let them learn with happy. It is made of material, which is durable and lasting for use. Features - Color: Transparent. - Material: ABS. - Size: About 31.00X2.00X2.00cm/ 12.18X0.79X0.79inch. - Colorful glowing, cool and interesting. - Simply place your hands on both ends of the bar to light it up . - It will make a mysterious sound, attract kid's attention. - children to explore the mystery of the circuit. - Able to improve children's scientific cognition. Package list: 1 x energy tube 1 x storage case 1 x set of spare button battery