Polk Audio UltraFit 500 Headphones - Black (ULTRAFIT 500BLK) High Performance Digital Sound - Surprising detail and fidelity to maximize performance. Connectivity Technology: Wired SecureFit Support - Exercise or play knowing your headphones will stay comfortably in place. Ultra Flexible Tangled-Free Planar Audio Cables - Avoid cable tangle and unwanted microphonics with oxygen-free cables in two custom lengths. StrainGuard - Kevlar core and computer designed transitional connections eliminate cable failure Moisture Shield - Resists moisture and keeps performing through strenuous activity.