Sennheiser AVX-Combo SET-4-US. Microphone type: Handheld/Lavalier microphone, Microphone frequency response: 20 - 20000 Hz. Receiver type: Camera mount receiver. Radio Frequency (RF) range: 1920 - 1930 MHz, Total Harmonic Distortion (THD): 0.1%, Signal-to-Noise Ratio (SNR): 90 dB. Battery technology: Lithium-Ion (Li-Ion). Cables included: USB