... , tour guides, conference, Interpretation, training 200m distance Product Description for Tour guide system with clear voiceguided tour system, whisper tour ... 150-200m3. Anti-interference4. Hi-fi acoustic quality, has battery display.5. High tone quality.6. Digital audio with 64K ... channel. Latency less than 0.5ms7. Our Li-battery can last/work for 12 hours at least.8. Application:Conference, Meeting ...