Over charge protection, Short circuit protection. It will protect batteries from the damage and the lifetime of batteries will be longer.Portable and light, charge at any time you want, and it is very convenient to carry. You can charge in multiple ways, such as computer, power bank and vehicle power supply.The batteries allows you to use more time to increase your flight experience. Package Includes:1x Drone Battery Material:Pure CobaltSize:Approx.5.5x3x1cm/2.17x1.18x0.39inchesFor Syma X5 X5C X5sw X5sc X5s X5sc -1 X5hw X5uw M18 H5PColor:Black/White 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.