Features: Over charge for protection, Short circuit for protection. It will protect batteries from the damage and the for lifetime of batteries will be longer. Portable and light, charge at any for time you want, and it is very convenient to carry. You can charge in multiple ways, such as computer, power banks and vehicle power supply. The batteries allows you to use more for time to increase your flight experience. Specifications: Material:Pure Cobalt Size: Approx.4x2.5x0.8cm/1.57x0.98x0.31in Voltage: 3.7V Ability:1000mah For Syma X5 X5C X5SC X5SW TK M68 CX-30 K60 905 V931 RC Quadcopter Drone Spare Part Package Includes: 1x Drone Battery note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thanks for your understandings.