■ Learning Materials Artec Art Lab Observation Science School Educational Toys Learning The Difference between Free Research Exchange and DC Current via LED! ■ An experimental device that observes the difference between AC and DC by checking the difference between AC and DC when the red and green LED lights are illuminated. Product Size: 1.2 x 5.9 x 0.08 inches (30 x 150 x 2 mm) (excluding LED), Cord Length: 3.3 - 6 V; Power Supply: AC DC; Product Size: 1.2 x 5.9 x 0.08 inches (30 x 150 x 2 mm); Cord Length: 3.3 ft (1 m); Material: Acrylic, Country of Origin: China.