The exclusive set for the LEGO Inside Tour - 2011.
Very cool and relevant set... I've seen the REAL ones :D
The set consists of two moulding machines, the first was a replica of the original hand operating injector back from 1949. The second, Larger one is copy of the current Moulder that LEGO uses today that ... well made the bricks that made this model :)
Each model has working features - the little one can 'press' the mould together. Where as the large one has a little slot to put in 1x1 round plates in (or raw abs) , followed by a separate mechanism to 'press' the mould together. the little 1x1 round then drops down an incline and into the yellow basket below - where it waits to be whisked off by machines to storage.
For anyone that can't make a tour, there's a fantastic documentary on LEGO which includes a lot of what we saw on the tour:
Time Lapse of build: www.flickr.com/photos/si-mocs/5794836577/in/set-721576267...