The 7-1440 Primary and Secondary Coil allows you to experiment with Transformer Principles and Induction.
The outer coil is 4-1/2" tall and 2-3/4" in diameter. The inner coil is 3-3/4" tall and 1-1/4" in diameter. The removable steel core with handle is 1/2" in diameter and 5-1/2" tall. All coils are wrapped with 20-gauge magnet wire with insulated binding posts as connectors. (5-1/2" x 3" x 2-1/2").