Sol Republic Relays Sport Wireless earbuds offer a premium audio experience for your workouts, whether you're outdoors or at the gym. They feature a secure fit with four sizes of ear tips and a cinch to keep them in place during your most intense workouts. With up to 12 hours of battery life, you can power through even the longest training sessions without worrying about running out of juice. And with Bluetooth connectivity, you can easily connect to your smartphone or other devices to stream music, take calls, and more.