1-8S Lipo Battery Voltage Tester

From the shop's description

1-8S Lipo Battery Voltage Tester and Low Voltage Buzzer Alarm 1-8S Lipo Battery Voltage Tester and Low Voltage Buzzer Alarm combo is easy to use. can save your model/batteries and investment. This is a new product combining all the voltage measurements with low-voltage alarm function. Li-Po Battery Voltage Buzzer Indicator: directly plug it into your operating battery, it will monitor the conditions of your battery all the time, so your batteries shall remain within safe operating voltage range at all times. Specifications: Low voltage Buzzer alarm mode for 2-8S. With a push key by which you can change the value settings and save. When voltage is below the set value, it will buzzer very loudly with red LED light. (pre-set value is 3.3V) Mini shape, no larger than a common key. Compact, easy to carry. Really useful in flight if you can?t see the lights. Use for 1-8s Lipo/Li-ion/LiMn/Li-Fe. Voltage detection precision: ?0.01V Unit voltage display range: 0.5-4.5V Total Voltage display Range: 0.5-36V 1S test mode voltage range: 3.7-30V 1S test mode detection precision: ?0.5% Alarm set value range: OFF 2.7-3.8V