MAG-MATE On/Off Magnetic Square Mag 90 WS0150R - The Home Depot
50kg Magnetic Force Mini Type Magnetic Holder With On/off Switch - Magnetic Materials - AliExpress
Adjust-O™ Magnet Squares - Strong Hand Tools
Industrial Magnetics, Inc. - DynamicLift™ Magnet
Strong Hand Tools - Str-7089 , Heavy Duty, Adjust-O Magnet Square, On/Off Switches, Pull Force: 160 lbs, 6" x 5-1/8" x 1-3/8", MSA48-HD: Magnetic Sweepers: Amazon.com: Tools & Home Improvement
90 lb. Rated Heavy Duty On/Off Large Welding Magnet