This pre-assembled DC motor is designed for students to learn about electromagnetic forces. The open structure resembles the diagram found in many textbooks. The polarity of the magnets can be reversed to change the direction of rotation. The motor can also be used with a rheostat to observe the change of speed with the change of current. The DC motor can stand vertically or horizontally and operates on a 1.5V battery (not included). It includes a sturdy plastic storage case and an activity guide. Shipping weight: 11.45 oz. Dimensions: 5.5" x 4.5" x 2.5".