Sennheiser SKM 835S AVX, Digital remote control AVX series, With dynamic MMD835 capsule, Polar pattern:Cardioid, Mute switch, Independent configuration, Auto frequency managent, Automatic input and output level, AES 256 signal encryption, Operation via supplied battery pack BA10, Operating time up to 15 hours, Frequency range: 1880 - 1930 MHz, Incl. battery pack BA10 and microphone holder