You are looking at a new in the package K-Line Supersnap 10" straight uncoupling section for O gauge. The packaging says it is compatible with all tubular track, but be aware it may take some modification if you are using with other three rail O besides SuperSnap.
Comes with the button, wire, and instructions.
If you have K-Line Supersnap or Shadowrail and need more, now is the time to buy it since K-Line is no more. Lionel, who now "owns" K-Line, will probably not continue its track lines.
Note: I do not think this would hook up to Lionel's new Fast Track.
CONDITION: C-10, new. Unused in the packaging. Some packaging may show tears, creases or other shelfwear.