How do you choose the correct swim fins? Kiefer carries two types: short blade fins and long blade fins. Short blade fins, such as Kiefer Power Fins, Kiefer Training Fins, Speedo Short Blade Training Fins, and Finis Zoomers, are designed to help fitness swimmers and competitive swimmers develop kick strength and ankle flexibility. Long blade fins are recommended for overall leg muscle conditioning and maximum propulsion, making them a great choice for general aquatics programs, scuba divers, and younger beginning swimmers. No matter what kind of swimmer you are, Kiefer has the perfect fins for your swim team, personal training, or aquatics program.