Battery for Xact Communication Wristlinx x3x, Wristlinx x2x, Wristlinx x33xif-2, Wristlinx x33xif, Wristlinx x3x-2, xb10, Wristlinx x2x-2, x3x Wristlinx, x33xif Wristlinx, x2x Wristlinx Capacity: 550mAh Type: Li-ion Volts: 3.7V Size : 47.87 x 30.02 x 4.47mm Certificated with ISO9001, RoHS & CE;