Riedel RUN-E1L XLR4F - in-ear headset (listen-talk combination) for applications in high noise environments, microphone with noise cancellation, fully adjustable microphone boom, frequency range listener: 200 - 5000 Hz, impedance listener: 145 Ohms, max SPL listener: 100 dB, frequency range microphone: 100 - 10000 Hz, impedance microphone: < 2. 2 ohms, max input SPL microphone: 110 dB, microphone characteristic: omnidirectional, microphone type: electret, left version; weight: 53 g, color: black, optimized for use with Bolero Intercom System