Your Basic Winning Performance. No bells & whistles, just astounding, surprising audio performance from a headphone bud. Not to mention all the extras that Polk has developed to take headphones to the next level of performance and durability. The UltraFit 500 positions itself comfortably in your mid-flange, not "in," and not "on," but exactly where you want it. The unique SecureFit ear hook design holds it in place so you can just forget about it, even during your most outrageous workouts. State-of-the-art moisture resistant materials technology wicks away performance-robbing sweat, and keeps the UltraFit 500 performing at peak levels for years of great sound. Big sound, small buds, high tech innovations, all in one tiny package: the UltraFit 500! No bells & whistles, just astounding, surprising audio performance from a headphone bud. Not to mention all the extras that Polk has developed to take headphones to the next level of performance and durability. The UltraFit 500 positions itself comfortably in your mid-flange, not "in," and not "on," but exactly where you want it. The unique SecureFit ear hook design holds it in place so you can just forget about it, even during your most outrageous workouts. State-of-the-art moisture resistant materials technology wicks away performance-robbing sweat, and keeps the UltraFit 500 performing at peak levels for years of great sound. Big sound, small buds, high tech innovations, all in one tiny package: the UltraFit 500!UltraFit