Signstek 0.2W Portable Stereo FM Transmitter Power Long Broadcast Range The Power output is 4 levels adjustable; choose different power in different situation can avoid interference to the environment around. This transmitter uses 1000ma Li-on battery, its high capacity enables a long working time up to 16hours at the lowest power output mode. Designed with bot Stereo and Mono audio output, both line-in and microphone volume is adjustable by pressing the botton on the case. It is especially suitable for application area such as tourism, meeting room, campus, driving school, teaching stadium, etc. Features at portable size, high quality, long broadcasting range and stable performance.