Features: The Alarm sounds and red lights to warn you when the battery voltage is too low. It can prevent your lipo battery damaged due to low voltage. This Lipo Battery Alarm is only good for 2 Cells 7.4V and 3 Cells 11.1V and 4 Cells 14.8V Lipo Batteries. Required the balance charger plug in the battery Each LiPo has a Minimun discharged voltage of 3.0V before damage occurs Each LiPo cell = 3.7V (nominal) no matter how many cells are in parallell. Each LiPo cell has a Minimun charged voltage of 4.25V before damage and Risk Of Fire occurs Specification: Original box: NO Weight: about 4g Color:Red Package Content: 1x lipo battery Low voltage buzzer Alarm