From the Manufacturer:

1. 3.7v 750mAh lithium batteries for MJX X400-V2 Quadcopter
2. High quality and practical.
3. Durable,rechargeable and works perfectly with the drone.
4. High capacity and long service life
5. Provide your drone continuous power for steady and well-balanced flying
6. Considering that you may have a plurality of batteries, so this additional charging USB cable will help you saving time while charging multiple batteries.

Specifications:

1. Model: X400-V2
2. Type: Lithium-Ion
3. Suitable for: MJX X400-V2 Quadcopter
4. Color: Silver
5. Capacity: 3.7v 750mAh.

Package Includes:

2 x Lithium-Ion Batteries
1 x USB Charger Cable

• Replacement batteries,perfectly compatible with MJX X400 Quadcopter
• 3.7V 750mAh lithium battery,high quality and well performance.
• Durable and pratical battery, rechargeable with long life using.
• Additional charging USB cable,more convenient for you to charge multiple batteries.
• Package include: 2pcs X400-V2 batteries+1pcs USB cable

Replacement batteries,perfectly compatible with MJX X400 QuadcopterMJX