Description Wireless Headset Battery Application Wireless Headphones Original Brand Sony Chemistry Nickel Metal Hydride Voltage 2.4V Nominal Capacity 700mAh Brand Master (this product is a compatible alternative to that of the original brand) Width 23.3mm Height 11.6mm Length/Breadth/Depth 46.6mm Weight 25g Suitable For: Sony MDR-RF4000, MDR-RF4000K, MDR-RF810, MDR-RF810RK, MDR-RF840, MDR-RF840RK, MDR-RF850, MDR-RF850RK, MDR-RF860, MDR-RF860RK, MDR-RF925, MDR-RF925RK, MDR-RF970, MDR-RF970RK Compatible With: Sony BP-HP550-11 battery