From the office to the gym, you can enjoy your favorite audio all day with the OnePlus Bullets Wireless Z In-Ear Headphones. The Bullets Wireless Z headphones deliver up to 20 hours of power on a full charge and are IP55 rated for sweat and water resistance. Music, podcasts, and more are engineered to sound great out of the 9.2mm dynamic drivers and super bass built into each earbud.