... than 0.5msFeatures and Advantage: 1.wireless tour guide system, audio guide system,teacher wireless microphone2. UHF digital wireless transmission ... hours at least.8. Application:Conference, Meeting, education, tour guide and factory etc.9. Packing details: One storage suitcase ... charging suitcase can put 20 pcs Receivers and 2 Transmitters.Certification: CE,ROHS,FCC,GSPayment terms and service:1. ...