Because it only permits drive power for the few seconds needed to reliably change a Cobalt Classic or Cobalt iP Analog point motor or other device it is controlling

Here is an LGB 40810 G Scale Coca-Cola Tank Car w Metal Wheels

2 cm / 5-5/8

Here is a MTH 30-78063 Blue Hen Beer Reefer Car

The Trainz SKU for this item is P11594191

IHC 9005 HO Coach Passenger Car Interior 1920 VariantsUnitPrice_number_327.27 Because it only permits driveThis is a IHC 9005 HO Coach Passenger Car Interior 1920 Condition: Factory New (C 9) Operational Status: Functional Original Box: Yes (P 9) Manufacturer: IHC Model Number: 9005 MSRP: $18. 99 Scale Era: HO Scale Model Type: Accessories The Trainz SKU for this item is P12372073. Trainz Product Id: 12372073