SPYALRM Common Sense RC Cell Spy Alarm - 8S Audio Voltage Tester. Our new Cell Spy Alarm doubles as both a voltage tester and a low-voltage buzzer in one compact, easy-to-use package!
 The digital readout displays individual cell voltages for up to 8 cells as well as your battery's total voltage. The Cell Spy Alarm can also read the cell voltage of 1S batteries with Ultra Micro connectors. Best of all, the Cell Spy Alarm doubles as an onboard low-voltage buzzer to protect your LiPo's from being over-discharged during use. Just set the alarm to the minimum voltage you're comfortable with (between 2.7 and 3.8 volts) and the buzzer will sound when your cells have been discharged to the limit you've selected.

 - Good for use with Lipo/LiMn/LiFe from 1S-8S
Low voltage alarm works from 2S-8S
Cell Voltage Display Range: 0.5-4.5V
Total Voltage Display Range: 0.5-36V
1S Mode: 3.7-30V
Alarm Settings: 2.7-3.8V or OFF
Dimensions: 42mm x 25mm x 13mm
Weight: 0.35oz (10g)