We still have a DC29. You should probably get the answer to your question from Dyson.
With the DC29, we now use the Dyson Triggerhead floor nozzle, item 5653972. This has so far proved much better (drive) than the Dyson floor nozzle with the additional complicated switching from floor to carpet. With Dyson spare parts, it is unfortunately always difficult to find the article number that is unique to the illustrations and names.