Finder 2 can power itself to beep even the quad battery has been ejected. It built-in light sensor can detect light intensity and then smartly control the LED light to flash. Buzzer automatically enter into sleep mode at night to save power and not disturb. Much Louder than Standard Buzzer. To easily find the crashed quad in long distance, Finder 2 is designed to install a very loud beeper that the dB is over 100. Model:Finder 2 Item Name:5V Buzzer for RC Drone Built-in Battery & LED Light Volume:Up to 105dB Working Time:Up to 30 Hours Charge Time:1.5 Hours Battery:80mAh Lipo Input Voltage:4.5-8.5V Weight:5g Two to Disarm the Buzzer: Option 1, Disarm with button: Disconnect main battery, hold disarm button on Finder 2 for 1-5 seconds then release. Option 2, Disarm with main battery: Disconnect main battery, then connect main battery for 3-6 seconds and disconnect it again. Compatible with for Both FPV quadcopter and RC Airplane - finder 2 is programmed to be compatible with any flight controllers to support FPV quad, and receivers for RC airplane. No extra setting required, it will automatically recognize the device to connect. Due to different batches, there may be differences in product appearance, color, and printed text, which will not affect the use. Colour:Random Color(Color is random and cannot be specified) Material:PCB Size:24x13x16mm Package Contents: 1 * Finder Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.