Case: Its 1300mAh internal battery can recharge the entire system multiple times for a total battery life of 30 hours. Audio is transmitted via 2.4 GHz frequency up to 1000' away. Easily capture 24-bit, 48 kHz audio with a 70 dB signal-to-noise ratio and 116 dB SPL. The camera-mount, dual-channel receiver features an integrated camera-mount interface. A 3.5mm TRS output port records audio directly to your device of choice. The transmitters feature 85mAh internal batteries with 9-hour battery life. The camera-mount receiver features a 145mAh internal battery with a 8.5-hour battery life. Connect your LARK M2 system to the LarkSound App to adjust parameters like volume and noise cancellation, update firmware, or check real-time audio statusall from your iOS or Android compatible smartphone.