I bought these from a railroad collector so I believe they are railroad related. I could not find a lot of information on them. Very heavy made of metal. Both still turn. Message me if you need more information.
External sensors for Speedometer (v211 and up) for many popular scales
Speed Controller for Model Trains. PWM. 12v. With Reversing Switch Attached.
1978 AIRFIX SPEED CONTROLLER FOR MULTI TRAIN CONTROLLER
Hornby R7229 DC Speed Controller for Analog Trains and Accessories
BASSETT LOWKE Resistance / Speed Controller for Electric Locomotives - O Gauge
Marklin 30v tranformer speed controller - for train models - untested
