1. Work as both normal and standalone buzzer - for Finder 2 can work as a standard buzzer that be controlled by your radio. It also can beep automatically when it detects the main battery has been ejected. 2. Super loudly, 110dB volume - for Finder 2 installed a very loud beeper that the volume is almost 110dB, it is much louder than standard buzzer. 3. LED flash automatically when darkness - The built-in light sensor can detect light intensity and then smartly control the LED light to flash. It be very helpful to find the quad in darkness. 4. Be compatible with both FPV quadcopter and RC Airplane - for finder 2 is programmed to be compatible with any flight controllers to support FPV quad, and receivers for RC airplane Why choose for Finder 2 instead of other drone buzzers After numerous optimization and update, for Finder 2 would be the most intelligent and reliable drone buzzer on the market. It installed a very loud beeper that the volume can be up to 110dB. It can help you find the lost quad easily even when your drone battery has been ejected. The built-in light sensor can detect light intensity and then smartly control the LED light to flash, it be very helpful when you need to find the lost quad in the darkness. The algorithm of for Finder 2 is highly tuned that the working time can reach 30 hours while other drone buzzers only can work for several hours. for Finder 2 is the most popular self-powered drone buzzer and highly recommended by pro pilots and hot FPV reviewers like Joshua Bardwell. Weight:5 grams Volume:Up to 110 dB Working time:Up to 30 hours Charge Time:1.5 hours Input Voltage:4.5 - 8.5 V Colour:Black Red Material:PC+Metal Size:24x13x16mm Package Contents: 1 * Buzzer Only the above package content, other products are not included.