This set contains small snowmobile with functional steering and chain. On snowmobile fit two minifigures, these can be also part of the set, it could be rescue-crew.
Most complicated for me was rear suspension. I tried to make it already many times but first I bought Pneumatic T Piece I achieved fully functional chain in small scale. Chains actually roll, but only on some surfaces like textil, skin or carpet.
Second problem was steering, I made more versions, only this with Lego Technic parts was functional and good fixed too.
Part of this set could be also some stickers (Rescue, Red Cross, Lightnings ect.).
More photos of this set you can found in my Flickr set and Google+:
And on YouTube are two videos that show this Snowmobile in motion and how it is made: