Theres a neater electromagnet made by Rapido but they are pretty scarce at the best of times
railsofsheffield.com

Railcrew On-Off Remote Uncoupler
The RailCrew ON-OFF Remote Uncoupler sits under the roadbed to reliably uncouple locomotives, passenger or freight cars, no matter what brand of standard magnetic knuckle couplers you use. At just 1 3/4″ wide (44mm) and 7/8″ deep (22mm) it’s not much larger than a permanent magnet and can be...
