Aqualogix Medium Resistance "All-Purpose" Fins: Ideal for those focused on combining strength training and high-speed cardio/HIIT. The Medium Resistance "All Purpose" Hybrid Fin is the newest addition to our line of functional aquatic resistance equipment. The All Purpose Fins provide a great balance of good resistance for knee hinge movements and also long lever hip articulation. You achieve results with high speed water exercises, dynamic neuro-muscular training, athletic performance training, rehabilitation and injury recovery pool training.