QCell 2x Samsung Galaxy S2 T-Mobile T989 1900mAh Slim Battery + FREE Universal Battery Charger (NOT Compatible with i9100/D710/i777) T-Mobile Galaxy S2 Slim Battery by QCell Premium Quality and Design Designed in Canada. Slim Profile Design with Maximum Cell Efficiency Comes with Free Universal Battery Charger - Charger includes USB port for microUSB charging DYNAStop overcharge IC stopper built in Voltage: 3.7V / Premium Quality and Best Material used