Demonstrates how electric current can be used to generate very strong magnetic fields. The precision machined contact surface makes this electromagnet so strong that it generates tremendous lifting power. The electromagnet is consists of core and yoke with vertically fitted four 'D' type cell holders around the electromagnet. The core has a cylindrical coil wound with enamelled copper wire on annular insulated bobbin. Batteries not included , It can also be operated with 4-6V/2 amp. DC power supply.