The main body of the furnace is between 6 and 6 1/4 inches tall, 4 1/8 inches wide, and 4 1/2 inches long. Factor in the pipes (which aren't removable) and it's about 10 inches tall and 5 1/2 inches wide. The style is incredibly realistic, and will serve as a great backdrop to any other realistic figures you might have. While 7 inch figures are about as tall you'd probably want to go, I imagine this piece would still work great with 1/18th scale figures.
Since this is a rotocast diorama piece, there really is only one moving part: the door to the boiler itself is hinged, and can open and shut easily and safely. I don't think you'll have to worry about breakage here unless you're really rough with the piece. I kind of wish the valve on the side of the pipes turned, but it doesn't. It's simply one solid piece.
The furnace doesn't have any extra pieces with it, but it does have a rather cool action feature: a working LED light inside the furnace. Underneath the display is a switch (and the battery cover) allowing you to turn on the interior light. The led glows an eerie yellowish orange and flickers a bit. The rear interior of the furnace is covered with a reflective material that amplifies the light and gives the furnace even more of a glow. This is a great feature, although I do wish that NECA had chosen to sculpt something a bit more flame like for the bulb, as the bulb we have simply looks like a battery operated tea light. Still, when you start taking pictures of this and using it in a diorama, you'll be thrilled.
Big Bad Toy Store, so at that price it's an even better value. I actually only own two A Nightmare on Elm Street figures: the McFarlane Movie Maniacs Freddy Krueger and the NECA Freddy Krueger from the remake. Sounds like I need to hunt around and pick up a few more.