I got this wireless microphone free as it was a part of the deal when I purchased my DCR-SR100. I have to admit that using this really clarifies the sound, especially when there is a situation with a lot of people and you want to hear your subject more than the background noise.
First, the receiver. Its very light (2oz.) and requires no additional batteries. It is powered by the camcorder and ONLY fits Sony's "Active Interface Shoe." **Only newer Sony Models are compatible, need to check if your model works** The receiver has two "on" selections. The first "on" is compatible with 5.1 dolby digital surround sound; it takes the voice information from the wireless trasmitter and plays it as your center sound from your 5.1 system. There is another "on" selection that will not differentiate which speaker the voice comes from but works just as well. The receiver also has a headphone jack so you can monitor what is being said from the transmitter; this can be extremely useful and since Sony has excluded ths feature from most of their camcorder consumer line, its a nice little option to have back.
Now the wireless transmitter can be connected to the person/ object in three different ways; a clip, a lanyard and a arm band. The transmitter also has a windscreen that I keep attached all the time; I find that this reduces that irritating rustling noise and cuts down on heavy breathing. I use the clip as much as possible since it keeps the transmitter steady and in one location. The arm band is second most since it minimizes movement but sometimes becomes obvious depending on the clothing. The lanyard is my least used because it constantly swings from side to side and increases unwanted noise. The transmitter uses 2 (AAA) batteries and is said to last about 3 hours. The transmitter is extremely light and easy to conceal using the clip.
As with all bluetooth items, line of sight is "key". The maximum range between the receiver and transmitter is said to be 100ft with direct line of sight. I tested this product by placing the transmitter in a room full of people and taking my camcorder outside (I had both a dining room and kitchen between myself and my transmitter and had the double paned glass sliding door closed) and was approximately 50 ft. away; I could hear everything without any problems.
One very, very minor thing that I have an easy fix for is that constant blue light that emits from both the receiver and transmitter. The transmitter is easily covered by the windscreen, but the receiver is completely exposed as it sits on top of the camcorder. I simply cover the receiver's light by using a piece of electrical tape, it seems to have no effect on performance and does not leave any sticky residue. I don't want to be that inconsiderate videographer parent that irritates the other parents during a play or recital.
I'm lucky that this is compatible with my model camcorder, but I still wish that Sony would minimize it proprietary grip on most of its products and technology.
Still a very nice product and I highly recommend it.
Hope this helps