Main Function:<br />1. When testing voltage > 3.6V? 2S Li-Polymer battery 2 green LED keeping light<br />2. When testing voltage > 3.6V? 3S Li-Polymer battery 3 green LED keeping light<br />3. When testing voltage > 3.6V? 4S Li-Polymer battery 4 green LED keeping light<br />4. When voltage <br />    Specifications<br />Specifications<br />  Type: Batteries                                                  <br />                        Feature: Tools/accessories of radio control series toy                                                 <br />Dimension and Weight<br />  Product Weight: 0.004 kg                                                  <br />                        Package Weight: 0.024 kg                                                  <br />                        Product Size (L x W x H): 4.0 x 2.0 x 1.0 cm / 1.6 x 0.8 x 0.4 inches                                                  <br />                        Package Size (L x W x H): 2 x 5 x 2 cm                                                 <br />Package Contents<br />  Package Contents: 1 x Loudhailer Low Voltage Buzzer                                                 <br /><br /><br /><br />                                                <br />