Features 1、Applicable Model: 3.7V 520mAh lithium battery is suitable for Wltoys V977, XK K110, XK K110S remote control helicopter. 2、520mAh Capacity Battery: RC helicopter battery capacity is 520mAh, upgraded large capacity battery, provide longer service life. 3、Strong Battery Power: Violent battery, strong power, stable and reliable performance, providing you great using experience. 4、Replacement Parts: Easy to install and disassemble, you can directly replace the old or damaged parts to obtain higher strength. 5、Light and Portable: Light in weight, small in size, easy to carry, will not increase your burden, can bring you more convenience. Item Type: RC Helicopter Battery Material: Lithium ion, Plastic Color: Blue Weight: Approx. 123g / 4.3oz Battery Size: Approx. 58.5x16.7x6.5mm / 2.3x0.7x0.3in Capacity: 520mAh Application: Suitable for Wltoys V977, XK K110, XK K110S Remote Control Helicopter Package List 6 x Battery 1 x Charger 1 x Charging Cable