This lithium-ion battery is compatible with the following Sony Ericsson models : K550i, K790a, W300i Specifications : Rechargeable lithium-ion battery. Capacity : 900 mAH, 3.7V No memory effect. (Does not need to be fully discharged before recharging) Talk time : up to 75 minutes Standby time : up to 50 hours Gives your phone the power to keep on fulfilling your communication needs. Perfect as a handy extra or replacement battery. * Equivalent to OEM batteries (MPN : BST-33).