Tera 3.7V 650mah 20C Li-po Battery for Syma X5 X5A X5C Quadcopter Capacity: 650mAh Voltage: 3.7V 20C continuous discharge Dimension: approx.41x25x8mm/1.6x1.0x0.3" Suitable for Syma X5, X5A, X5C Quadcopter.