Features 1、Lithium Ion: Made of premium plastic and lithium ion, the RC helicopter battery kit is light in weight, durable, reliable, practical and has a long service life. 2、Suitable: The RC helicopter 3.7V batteries are suitable for WLtoys V977, XK K110, XK K110S, you can use it for corresponding remote control helicopter. 3、Large Capacity: The RC helicopter 520mah batteries has large capacity, can be used for a long time, make your RC helicopter more lasting. 4、Replace: The RC plane lithium ion battery can be used for replace the old or damaged parts, easy to install and dismantle, convenient and practical. 5、Powerful: The RC helicopter battery for WLtoys V977 is powerful, equipped with charger and charging wires, has long battery life. Item Type: RC Helicopter Lithium Ion Battery Material: Plastic, Lithium Ion Weight: Approx. 87g/3.07oz Color: Blue Size: Approx. 58.5x16.7x6.5mm/2.30x0.66x0.26in Voltage: 3.7V Capacity: 520mah Suitable: For WLtoys V977, XK K110, XK K110S Package List 4 x RC Helicopter Lithium Ion Battery 1 x Charger 1 x Charging Cable