Features: Use for 1-6s(3.7V-22.2V) Lipo/Li-ion/LiMn/Li-Fe Voltage detection precision:±0.01V Unit voltage display range:0.50-4.49V Total Voltage display Range:0.50-25.9V 1S test mode voltage range:3.3-13.2V 1S test mode detection precision:±0.5% Low voltage Buzzer alarm mode for 2-6S when voltage <3.3V,it will buzzer with red LED light Really usefull in flight if you can't see the lights