The Hybrid Reeflo pumps are a novel idea from the aquarium industry leader in high capacity direct drive water pumps. Now when you buy a Snapper pump it will come with the impeller for upgrading to a Dart and when you buy a Hammerhead pump it will also come with a Barracuda impeller. Since the Dart-Snapper and Hammerhead-Barracuda pumps use the same motor and impeller housing, it makes sense that Reeflo would streamline their products for easier stocking by fish stores and more long term value for end users.
If you have an older Dart-Snapper or Hammerhead-Barracuda you will also be able to convert your pumps by buying the impeller from Reeflo. You will absolutely be able to downgrade you Dart to a Snapper or a Hammerhead to a Barracuda but for upgrading the smaller size of each pair, you will just have to make sure that your motor has enough horse power for the upgrade. New impellers for current Reeflo owners cost $27 for the small and $30 for the larger version and the Hybrid Reeflo pumps are shipping now.