Door Holding Magnet, 24V DC, 110 lbs holding force - GTR050.750003
24V DC 200N 0.3LB Electric Lifting Magnet Electromagnet Solenoid Lift Holding - Walmart.com
Round Electromagnets 24 Volt | Bunting - eMagnets
1 31/32" diameter x 1 3/16" thick Energise to Release Electromagnet with M6 Mounting Hole - 88.2lbs Pull (24V DC / 100W) | Other from First4magnets.com