Hi Sunando,
Is this question related to your one about recording university lectures?:
http://www.daniweb.com/techtalkforums/thread30938.html
If so, you do not need any such product. Any reasonable microphone will do the job perfectly well. In that topic I mentioned using a portable tape recorder for the task a couple of decades ago. At that time the inbuilt microphone of a cheap cassette recorder was perfectly adequate for the task. Technology has improved since then.
Why do you say this is your first post here, by the way?