This Wireless Tour Guide System Is Designed Specially For Guides And Groups.It Is A Lightweight,Multi-Channel System That Helps Tour Participantslisten Directly To The Tour Guide Clearly,Enhancing The Wireless/Effortless Presentation Effect Between Guide And Participants. Features 99 Channels:195Mhz-230Mhz, Not 2.4G Which Is Easy To Be Disturbed.99 Selectable Channels, No Need Toworry About Signal Interference. Current Channel, Battery Level, Signal Level Can Be Shown. Avoid The Interference Of Other Frequencies Automatically. Small And Lightweight, Clearest Voice Transmission. 99 Ids Allow 40 Groups To Use Simultaneously. One Transmitter Can Work With Many Receivers. Application Tour Guiding, Wireless Meeting, Wireless Teaching ,Simultaneous Interpreting,Corporate Hospitality,Factory Tour,Field Interpretation,Governmental Agencies,Houses Of Worship,Conventions And Auditoriums,Etc. Specification Transmitter & Receiver: Frequency Range:195Mhz-230Mhz Output Power: 10Mw Power Supply: Dc 110-240V Power Input: 5V 1A Frequency Response:50-18000Hz S/N Ratio:=90Db(Typical) Frequency Stability:+/-0.005% Modulation Deviation:+/-75Khz T.H.D: