With a patented comfort system, the Jaybird X2 Sport IEMs are built for unrivaled comfort and sound quality when you're on the move. Wireless Bluetooth supports skip-free music and calls, and the earphones easily pair up to your devices via Sound Check technology. Super-capacity Battery HD technology allows for up to 8 hours of battery life. Plus, the system is designed to be sweat-proof for intense workouts. Multiple sizes of ear tips and fins are included, so you can find your perfect fit.