DJI Mic Mini. Microphone direction type: Omnidirectional, Maximum sound pressure level (1kHz): 120 dB, Equivalent noise level: 24 dB. Receiver type: Camera mount receiver. Transmitter type: Bodypack transmitter. Bluetooth frequency band: 2.4 - 2.4835 GHz, Maximum operating distance: 400 m, Audio output: 3.5 mm. Battery life (max): 10 h, Battery technology: Lithium-Ion (Li-Ion), Battery type: Built-in battery