You are looking at a Lionel 6-12931 Electrical Substation Building O/027. This is a neat KIT, a little more detailed and involved than the traditional Plasticville-type kit.
It makes for a very nice building in O scale for your Lionel layout. The neat thing about the Electrical Substation is that it can be a power substation, part of a power plant...lots of things. This series of Lionel building kits has been out of production for quite a while.
This one is still in the original box with the contents still sealed. That is how you want your kits! And it has the original instructions, too.
NOTE: This is a kit you will need to put together.