This past weekend, I replaced the old stock needlewheel with the new and improved needlewheel from Reef Specialty on my Orca 250 Pro model skimmer. The new needlewheel really improves the skimmer's performance over the stock needlewheel. The new needlewheel seems to push the effluent out of the neck much better than the stock unit. The replacement was very easy to do. I would definitely recommend this upgrade to an already great skimmer.