Optional UHF band 640-690MHz. * Unique digital 16 bit ID pilot technology, no crosstalk disturbance even in the same frequency. * LCD display on receiver show frequency and battery condition. * Adopt Single chip design, with true diversity function to avoid dead point. * Auto frequency scanning and user set frequency function. * Suitable for stages, ballrooms, conference rooms, speech and home entertainment. * Ideal distance: longer than 80M in open space.