HQRP Battery for Sony MDR-RF925 MDR-RF925R MDR-RF925RK MDR-RF970 MDR-RF970RK MDR-RF811 MDR-RF811RK Wireless Stereo Headphone System + HQRP Coaster HQRP&reg; Rechargeable Battery plus HQRP&reg; Coaster; Battery Voltage: 2.4V; Capacity: 700 mAh; Ni-Mh; Compatible with Original Battery; 200 Days warranty! Headset is not included into our offer! Compatible with: Sony BP-HP550-11 fits MDR-RF4000 MDR-RF4000K MDR-RF810 MDR-RF810RK MDR-RF925, MDR-RF925R, MDR-RF925RK, MDR-RF970, MDR-RF970RK Wireless Stereo Headphone System, Sony MDR-RF840 MDR-RF840RK MDR-RF850 MDR-RF850RK MDR-RF860 MDR-RF860RK MDR-RF811 MDR-RF811RK MDR-RF970R Wireless Stereo Headphone System.