Sennheiser recommends this battery for owners of the RS 40, RS 45, RS 60, RS 65, RS 80, RS 85 wireless headphone systems and HDR 45, HDR 65, HDR 85 headphones. This battery is interchangeable so you can extend your listening time on these classic wireless headphones. Compatibility: RS 40, RS 45, RS 60, RS 65, RS 80, RS 85 wireless headphone systems Warranty: The BA 151 carries a 60 day warranty Why Sennheiser? For over 60 years every Sennheiser mic or headphone comes with a built-in mission: to stay true to the sound and soul the music was given by its artist. From the fragile intimacy of a whispered word to the deep and dark punch of an attacking bassline. Sennheiser delivers pure emotion and excitement. A quality that has convinced a broad spectrum of artists and of course music lovers all over the world. Sennheiser offers a great experience for everyone who really wants to hear.