This is a model of an N Scale truck mounted Re-Railer used to re-rail derailed trains. They are usually mounted on the locomotive trucks as shown in this image of UP’s GP20 No.475 taken by Joe Blackwell.
Here it is shown on an N Scale GP20.
The detailed parts comes in pairs and need to be separated before they can be fixed to your locomotive as an added detail as shown below.
Packs of this detail are available in three sizes…….
The kits are printed in the Shapeways FUD material which will require cleaning upon delivery, please see my FAQs for more information.