Chinatera 12v Dc Sucked Type Electric Lifting Magnet Electromagnet Solenoid 5 Styles (Style:P20/15) Material: Metal, Electronic Parts Style: P20/15, P25/20, P30/22, P34/18, P40/20 Diameter: Approx. 20mm, 25mm, 30mm, 40mm Center Diameter: Approx. 8mm, 10mm, 12mm, 18mm Height: Approx. 15mm, 20mm, 22mm, 20mm