Retekess T15B 5W/15W FM Transmitter Long Range Wireless Mini Radio Broadcast Stereo Station PLL Wireless Music LCD Display with AUX In Line Antenna for Church Home Car Christmas(Silver) 2-level RF power adjustable; Transmission frequency can be set from; the most transmission distance of 3-4 km (1.9-2.5 mi) in the open air; Fan noise is about 30 decibels Built-in PLL advanced modulation system support strong signal,Adjustable Magnetic antenna, easy to move the antenna to the outside, the roof, balcony or window, more effective transmission and reception of electromagnetic waves Heat dissipation; using high-quality dual ball bearing fan, reasonable heat dissipation channels, excellent thermal performance;When the temperature is too hot,bigger than 107.6, the display will show a Temperature Alarm,meanwhile the machine will start to sound the di di voice alarm PC control connect your computer by USB supporting intelligent broadcasting software, achieve diversification unattended broadcast; You can connect wireless to mobile phones, tablets and other wireless devices; With U disk play function, support lossless format FLAC/WAV, compatible with a variety of other commonly used formats This FM transmitter can work with any numerous fm device,such as fm radio,fm speaker;so it is suitable at a large church to broadcast iPod music to multiple outdoor fm radio speaker