Measuring 2.36" in length, this small U-shaped magnet is ideal for classroom demonstrations and physics laboratory experiments. Made of Alnico, which is an alloy composed primarily of aluminum (Al), nickel (Ni), and cobalt (Co), it is ferromagnetic, which is to say that it was formed into a permanent magnet. It has been carefully painted red on one half of the magnet and green on the other, to denote the north (red) and south (green) poles. The U-shaped magnet has approximate overall measurements of 2.36x2x0.4" (0.16" hole in the center), and includes a steel keeper bar to help protect the poles from damage or loss of magnetism.