Eisco Labs Solenoid Air Cored - Magnetism & Electromagnetism Eisco Labs Solenoid Air Cored - Magnetism & Electromagnetism Eisco Labs 15" Solenoid is wound with 270 turns of heavy gauge enameled copper wire of 1.25mm dia Equipped with 4mm sockets for power supply. Diameter 50 mm 270 turns wire 1.25 mm in diameter. Power Supply not included