The Scosche tuneIN is a small, portable FM transmitter that was primary made and designed to be used with iPods and other MP3 players, for use in the car. This is a common application for a simple, low-watt FM transmitter, but there is another great use for these FM transmitters, and that is with wireless monitoring. The cost of a very basic professional wireless monitor system can be over $300, but if you are looking for a cheaper alternative that works, try FM Transmission. Using a headphone amp, you can attach the Scosche tuneIN directly to the headphone out port, and the tuneIN will convert the signal automatically to FM. Then, you can use any portable walkman FM radio as a receiver, get a pair of great earphones, and you have a complete wireless in-ear monitor system, for under $100 for everything. The tuneIN itself is very cheap, I was able to purchase it for about $15.
The Scosche tuneIN also features an on/off switch, a switch to change the band, and it uses two AA batteries. The case is small and ergonomic, and there are no unnecessary ports or curves on the case. Of all the FM transmitters out there, this is one of the smallest ones, and it is ideal for in-ear monitoring setups, because it doesn't have an option for power through a car cigarette lighter, which can be common on most FM transmitters.
The audio quality of the FM transmission is surprisingly good, as long as the level is set correctly by the headphone amp that you are using. There are no gain or input volume controls on the tuneIN, and it can easily clip if you are not careful. It works best with a quality headphone amp with a level control and/or a mic gain control, depending on your setup.