TYR Split Training Fin Unlike conventional training fins that force the foot to push water in a flat plane (like an old paddlewheel), The Split Fin™ blades slice through the water with two winged surfaces, creating lift & forward propulsion (like a propeller). Engineered to evenly distribute resistance during the upswing & down thrust motions of the kicking cycle, the LFSPLIT Training Fins operate more efficiently than 'paddle' bladed fins by mimicking a user's natural kicking cadence & work both muscle groups equally to help build leg strength & maximize power output. Designed to function optimally with a tighter, higher frequency kick, The Split Fin™ Training Blades help simulate the natural 'turnover' rate an athlete can only achieve at race pace. The unique, flexible split blade allows sustained intense training over the course of your workout & helps reduce the ankle strain, fatigue & cramping often associated with the use of conventional 'paddle' fins. * For Female equivalent, please size down 1-2 sizes