Great for educating everyone on how colors mix. When turned on, the red, green, and blue colors come up in such a way that they intersect with each other. You can have 2 or 3 intersecting to show the resulting color. 4 inches by 2.5 inches by 1-3/4 inches high. Display globe is 1.8 inches diameter. Each color has an adjustable intensity control. Works off 6 volts DC. You can connect it to your power supply or use our included battery holder (needs 4 AA batteries). We included an spst switch so you can leave your battery pack connected and just turn off the device. Batteries not included. New.