Features 117 channels; 72MHz-76MHz Avoid the interference of other frequencies automatically. The smallest and lightest. The cleanest voice transmission. 40 IDs allow 40 groups to use simultaneously. Description Product Description Color: 1 Transmitter 80 Receivers Features 1.117 channels;72MHz-76MHz. 2.Avoid the interference of other frequencies automatically. 3.The smallest and lightest. 4.The cleanest voice transmission. 5.40 IDs allow 40 groups to use simultaneously. This Wireless tour guide system is designed specially for guides and groups.It is a lightweight,multi-channel system that helps tour participants listen directly to the tiur guide clesrly,enhancing the wireless/effortless presentation effect between guide and participants. 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:72MHz-76MHz Power Supply:DC3.7V Frequency Response:50-18000Hz S/N Ratio:¡Ý90dB(Typical) Frequency Stability:+/-0.005% Modulation Deviation:+/-75kHz T.H.D:<0.3%@1kHz Battery type:Built-in Lithium battery Battery life:15 hours Talk range:100 meters Package Contents 1x Transmitter 80x Receiver 1x clip-on microphone 80x earphone 81x charger 80x lanyard