I have one for O gauge track used for putting cars on the track, not for "re-rail". It is about 30 years old, made of plastic and orange. It is not a Lionel product, or at least there is no manufacturer identification. It actually lays on top of the O gauge three rail track when used.
Works great for little kids. Especially, with kids playing with fixed voltage rails and forgetting to turn power off before adding cars.
I'd throw a pic, but away from home on business.